Currently the best way to wait for the completion of a long-running
operation in a pool, like a scrub or device removal, is to poll 'zpool
status' and parse its output, which is neither efficient nor convenient.
This change adds a 'wait' subcommand to the zpool command. When invoked,
'zpool wait' will block until a specified type of background activity
completes. Currently, this subcommand can wait for any of the following:
- Scrubs or resilvers to complete
- Devices to initialized
- Devices to be replaced
- Devices to be removed
- Checkpoints to be discarded
- Background freeing to complete
For example, a scrub that is in progress could be waited for by running
zpool wait -t scrub <pool>
This also adds a -w flag to the attach, checkpoint, initialize, replace,
remove, and scrub subcommands. When used, this flag makes the operations
kicked off by these subcommands synchronous instead of asynchronous.
This functionality is implemented using a new ioctl. The type of
activity to wait for is provided as input to the ioctl, and the ioctl
blocks until all activity of that type has completed. An ioctl was used
over other methods of kernel-userspace communiction primarily for the
sake of portability.
Porting Notes:
This is ported from Delphix OS change DLPX-44432. The following changes
were made while porting:
- Added ZoL-style ioctl input declaration.
- Reorganized error handling in zpool_initialize in libzfs to integrate
better with changes made for TRIM support.
- Fixed check for whether a checkpoint discard is in progress.
Previously it also waited if the pool had a checkpoint, instead of
just if a checkpoint was being discarded.
- Exposed zfs_initialize_chunk_size as a ZoL-style tunable.
- Updated more existing tests to make use of new 'zpool wait'
functionality, tests that don't exist in Delphix OS.
- Used existing ZoL tunable zfs_scan_suspend_progress, together with
zinject, in place of a new tunable zfs_scan_max_blks_per_txg.
- Added support for a non-integral interval argument to zpool wait.
Future work:
ZoL has support for trimming devices, which Delphix OS does not. In the
future, 'zpool wait' could be extended to add the ability to wait for
trim operations to complete.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: John Gallagher <john.gallagher@delphix.com>
Closes#9162
Accidentally introduced by dc04a8c which now takes the SCL_VDEV lock
as a reader in zfs_blkptr_verify(). A deadlock can occur if the
/etc/hostid file resides on a dataset in the same pool. This is
because reading the /etc/hostid file may occur while the caller is
holding the SCL_VDEV lock as a writer. For example, to perform a
`zpool attach` as shown in the abbreviated stack below.
To resolve the issue we cache the system's hostid when initializing
the spa_t, or when modifying the multihost property. The cached
value is then relied upon for subsequent accesses.
Call Trace:
spa_config_enter+0x1e8/0x350 [zfs]
zfs_blkptr_verify+0x33c/0x4f0 [zfs] <--- trying read lock
zio_read+0x6c/0x140 [zfs]
...
vfs_read+0xfc/0x1e0
kernel_read+0x50/0x90
...
spa_get_hostid+0x1c/0x38 [zfs]
spa_config_generate+0x1a0/0x610 [zfs]
vdev_label_init+0xa0/0xc80 [zfs]
vdev_create+0x98/0xe0 [zfs]
spa_vdev_attach+0x14c/0xb40 [zfs] <--- grabbed write lock
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#9256Closes#9285
Adds ZFS_MODULE_PARAM to abstract module parameter
setting to operating systems other than Linux.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes#9230
When running on larger memory systems, we can overflow the value of
maxinflight. This can result in maxinflight having a value of 0 causing
the system to hang.
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes#9272
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Closes#9240
On systems with large amounts of storage and high fragmentation, a huge
amount of space can be used by storing metaslab range trees. Since
metaslabs are only unloaded during a txg sync, and only if they have
been inactive for 8 txgs, it is possible to get into a state where all
of the system's memory is consumed by range trees and metaslabs, and
txgs cannot sync. While ZFS knows how to evict ARC data when needed,
it has no such mechanism for range tree data. This can result in boot
hangs for some system configurations.
First, we add the ability to unload metaslabs outside of syncing
context. Second, we store a multilist of all loaded metaslabs, sorted
by their selection txg, so we can quickly identify the oldest
metaslabs. We use a multilist to reduce lock contention during heavy
write workloads. Finally, we add logic that will unload a metaslab
when we're loading a new metaslab, if we're using more than a certain
fraction of the available memory on range trees.
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#9128
When a pool is imported it will scan the pool to verify the integrity
of the data and metadata. The amount it scans will depend on the
import flags provided. On systems with small amounts of memory or
when importing a pool from the crash kernel, it's possible for
spa_load_verify to issue too many I/Os that it consumes all the memory
of the system resulting in an OOM message or a hang.
To prevent this, we limit the amount of memory that the initial pool
scan can consume. This change will, by default, use 1/16th of the ARC
for scan I/Os to prevent running the system out of memory during import.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: George Wilson george.wilson@delphix.com
External-issue: DLPX-65237
External-issue: DLPX-65238
Closes#9146
Deleting a clone requires finding blocks are clone-only, not shared
with the snapshot. This was done by traversing the entire block tree
which results in a large performance penalty for sparsely
written clones.
This is new method keeps track of clone blocks when they are
modified in a "Livelist" so that, when it’s time to delete,
the clone-specific blocks are already at hand.
We see performance improvements because now deletion work is
proportional to the number of clone-modified blocks, not the size
of the original dataset.
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Signed-off-by: Sara Hartse <sara.hartse@delphix.com>
Closes#8416
In the past we've seen multiple race conditions that have
to do with open-context threads async threads and concurrent
calls to spa_export()/spa_destroy() (including the one
referenced in issue #9015).
This patch ensures that only one thread can execute the
main body of spa_export_common() at a time, with subsequent
threads returning with a new error code created just for
this situation, eliminating this way any race condition
bugs introduced by concurrent calls to this function.
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#9015Closes#9044
= Motivation
At Delphix we've seen a lot of customer systems where fragmentation
is over 75% and random writes take a performance hit because a lot
of time is spend on I/Os that update on-disk space accounting metadata.
Specifically, we seen cases where 20% to 40% of sync time is spend
after sync pass 1 and ~30% of the I/Os on the system is spent updating
spacemaps.
The problem is that these pools have existed long enough that we've
touched almost every metaslab at least once, and random writes
scatter frees across all metaslabs every TXG, thus appending to
their spacemaps and resulting in many I/Os. To give an example,
assuming that every VDEV has 200 metaslabs and our writes fit within
a single spacemap block (generally 4K) we have 200 I/Os. Then if we
assume 2 levels of indirection, we need 400 additional I/Os and
since we are talking about metadata for which we keep 2 extra copies
for redundancy we need to triple that number, leading to a total of
1800 I/Os per VDEV every TXG.
We could try and decrease the number of metaslabs so we have less
I/Os per TXG but then each metaslab would cover a wider range on
disk and thus would take more time to be loaded in memory from disk.
In addition, after it's loaded, it's range tree would consume more
memory.
Another idea would be to just increase the spacemap block size
which would allow us to fit more entries within an I/O block
resulting in fewer I/Os per metaslab and a speedup in loading time.
The problem is still that we don't deal with the number of I/Os
going up as the number of metaslabs is increasing and the fact
is that we generally write a lot to a few metaslabs and a little
to the rest of them. Thus, just increasing the block size would
actually waste bandwidth because we won't be utilizing our bigger
block size.
= About this patch
This patch introduces the Log Spacemap project which provides the
solution to the above problem while taking into account all the
aforementioned tradeoffs. The details on how it achieves that can
be found in the references sections below and in the code (see
Big Theory Statement in spa_log_spacemap.c).
Even though the change is fairly constraint within the metaslab
and lower-level SPA codepaths, there is a side-change that is
user-facing. The change is that VDEV IDs from VDEV holes will no
longer be reused. To give some background and reasoning for this,
when a log device is removed and its VDEV structure was replaced
with a hole (or was compacted; if at the end of the vdev array),
its vdev_id could be reused by devices added after that. Now
with the pool-wide space maps recording the vdev ID, this behavior
can cause problems (e.g. is this entry referring to a segment in
the new vdev or the removed log?). Thus, to simplify things the
ID reuse behavior is gone and now vdev IDs for top-level vdevs
are truly unique within a pool.
= Testing
The illumos implementation of this feature has been used internally
for a year and has been in production for ~6 months. For this patch
specifically there don't seem to be any regressions introduced to
ZTS and I have been running zloop for a week without any related
problems.
= Performance Analysis (Linux Specific)
All performance results and analysis for illumos can be found in
the links of the references. Redoing the same experiments in Linux
gave similar results. Below are the specifics of the Linux run.
After the pool reached stable state the percentage of the time
spent in pass 1 per TXG was 64% on average for the stock bits
while the log spacemap bits stayed at 95% during the experiment
(graph: sdimitro.github.io/img/linux-lsm/PercOfSyncInPassOne.png).
Sync times per TXG were 37.6 seconds on average for the stock
bits and 22.7 seconds for the log spacemap bits (related graph:
sdimitro.github.io/img/linux-lsm/SyncTimePerTXG.png). As a result
the log spacemap bits were able to push more TXGs, which is also
the reason why all graphs quantified per TXG have more entries for
the log spacemap bits.
Another interesting aspect in terms of txg syncs is that the stock
bits had 22% of their TXGs reach sync pass 7, 55% reach sync pass 8,
and 20% reach 9. The log space map bits reached sync pass 4 in 79%
of their TXGs, sync pass 7 in 19%, and sync pass 8 at 1%. This
emphasizes the fact that not only we spend less time on metadata
but we also iterate less times to convergence in spa_sync() dirtying
objects.
[related graphs:
stock- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGStock.png
lsm- sdimitro.github.io/img/linux-lsm/NumberOfPassesPerTXGLSM.png]
Finally, the improvement in IOPs that the userland gains from the
change is approximately 40%. There is a consistent win in IOPS as
you can see from the graphs below but the absolute amount of
improvement that the log spacemap gives varies within each minute
interval.
sdimitro.github.io/img/linux-lsm/StockVsLog3Days.png
sdimitro.github.io/img/linux-lsm/StockVsLog10Hours.png
= Porting to Other Platforms
For people that want to port this commit to other platforms below
is a list of ZoL commits that this patch depends on:
Make zdb results for checkpoint tests consistent
db587941c5
Update vdev_is_spacemap_addressable() for new spacemap encoding
419ba59145
Simplify spa_sync by breaking it up to smaller functions
8dc2197b7b
Factor metaslab_load_wait() in metaslab_load()
b194fab0fb
Rename range_tree_verify to range_tree_verify_not_present
df72b8bebe
Change target size of metaslabs from 256GB to 16GB
c853f382db
zdb -L should skip leak detection altogether
21e7cf5da8
vs_alloc can underflow in L2ARC vdevs
7558997d2f
Simplify log vdev removal code
6c926f426a
Get rid of space_map_update() for ms_synced_length
425d3237ee
Introduce auxiliary metaslab histograms
928e8ad47d
Error path in metaslab_load_impl() forgets to drop ms_sync_lock
8eef997679
= References
Background, Motivation, and Internals of the Feature
- OpenZFS 2017 Presentation:
youtu.be/jj2IxRkl5bQ
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemaps-project
Flushing Algorithm Internals & Performance Results
(Illumos Specific)
- Blogpost:
sdimitro.github.io/post/zfs-lsm-flushing/
- OpenZFS 2018 Presentation:
youtu.be/x6D2dHRjkxw
- Slides:
slideshare.net/SerapheimNikolaosDim/zfs-log-spacemap-flushing-algorithm
Upstream Delphix Issues:
DLPX-51539, DLPX-59659, DLPX-57783, DLPX-61438, DLPX-41227, DLPX-59320
DLPX-63385
Reviewed-by: Sean Eric Fagan <sef@ixsystems.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: George Wilson <gwilson@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8442
If dedup is in use, the `dedupditto` property can be set, causing ZFS to
keep an extra copy of data that is referenced many times (>100x). The
idea was that this data is more important than other data and thus we
want to be really sure that it is not lost if the disk experiences a
small amount of random corruption.
ZFS (and system administrators) rely on the pool-level redundancy to
protect their data (e.g. mirroring or RAIDZ). Since the user/sysadmin
doesn't have control over what data will be offered extra redundancy by
dedupditto, this extra redundancy is not very useful. The bulk of the
data is still vulnerable to loss based on the pool-level redundancy.
For example, if particle strikes corrupt 0.1% of blocks, you will either
be saved by mirror/raidz, or you will be sad. This is true even if
dedupditto saved another 0.01% of blocks from being corrupted.
Therefore, the dedupditto functionality is rarely enabled (i.e. the
property is rarely set), and it fulfills its promise of increased
redundancy even more rarely.
Additionally, this feature does not work as advertised (on existing
releases), because scrub/resilver did not repair the extra (dedupditto)
copy (see https://github.com/zfsonlinux/zfs/pull/8270).
In summary, this seldom-used feature doesn't work, and even if it did it
wouldn't provide useful data protection. It has a non-trivial
maintenance burden (again see https://github.com/zfsonlinux/zfs/pull/8270).
We should remove the dedupditto functionality. For backwards
compatibility with the existing CLI, "zpool set dedupditto" will still
"succeed" (exit code zero), but won't have any effect. For backwards
compatibility with existing pools that had dedupditto enabled at some
point, the code will still be able to understand dedupditto blocks and
free them when appropriate. However, ZFS won't write any new dedupditto
blocks.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Issue #8270Closes#8310
Redacted send/receive allows users to send subsets of their data to
a target system. One possible use case for this feature is to not
transmit sensitive information to a data warehousing, test/dev, or
analytics environment. Another is to save space by not replicating
unimportant data within a given dataset, for example in backup tools
like zrepl.
Redacted send/receive is a three-stage process. First, a clone (or
clones) is made of the snapshot to be sent to the target. In this
clone (or clones), all unnecessary or unwanted data is removed or
modified. This clone is then snapshotted to create the "redaction
snapshot" (or snapshots). Second, the new zfs redact command is used
to create a redaction bookmark. The redaction bookmark stores the
list of blocks in a snapshot that were modified by the redaction
snapshot(s). Finally, the redaction bookmark is passed as a parameter
to zfs send. When sending to the snapshot that was redacted, the
redaction bookmark is used to filter out blocks that contain sensitive
or unwanted information, and those blocks are not included in the send
stream. When sending from the redaction bookmark, the blocks it
contains are considered as candidate blocks in addition to those
blocks in the destination snapshot that were modified since the
creation_txg of the redaction bookmark. This step is necessary to
allow the target to rehydrate data in the case where some blocks are
accidentally or unnecessarily modified in the redaction snapshot.
The changes to bookmarks to enable fast space estimation involve
adding deadlists to bookmarks. There is also logic to manage the
life cycles of these deadlists.
The new size estimation process operates in cases where previously
an accurate estimate could not be provided. In those cases, a send
is performed where no data blocks are read, reducing the runtime
significantly and providing a byte-accurate size estimate.
Reviewed-by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Prashanth Sreenivasa <pks@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Chris Williamson <chris.williamson@delphix.com>
Reviewed-by: Pavel Zhakarov <pavel.zakharov@delphix.com>
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Closes#7958
When an import requires a long MMP activity check, or when the user
requests pool recovery, the import make take a long time. The user may
not know why, or be able to tell whether the import is progressing or is
hung.
Add a kstat which lists all imports currently being processed by the
kernel (currently only one at a time is possible, but the kstat allows
for more than one). The kstat is /proc/spl/kstat/zfs/import_progress.
The kstat contents are as follows:
pool_guid load_state multihost_secs max_txg pool_name
16667015954387398 3 15 0 tank3
load_state: the value of spa_load_state
multihost_secs: seconds until the end of the multihost activity
check; if over, or none required, this is 0
max_txg: current spa_load_max_txg, if rewind is occurring
This could be used by outside tools, such as a pacemaker resource agent,
to report import progress, or as a part of manual troubleshooting. The
zpool import subcommand could also be modified to report this
information.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#8696
The 'zpool resilver' command requires that the resilver_defer
feature is active on the pool. Unfortunately, the check for
this was left out of the original patch. This commit simply
corrects this so that the command properly returns an error
in this case.
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Igor Kozhukhov <igor@dilos.org>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8700
When a pool is initially created (by `zpool create`), predictive
prefetch is inadvertently disabled, until the pool is export/import-ed,
or the machine is rebooted.
When device removal was introduced, we added some code to disable
predictive prefetching until indirect vdevs have been loaded. This
resulted in the "default state" of prefetch being disabled, until we
proactively enable it after indirect vdevs are loaded. Unfortunately
this resulted in a few bugs where in some code paths we neglect to
enable predictive prefetch. The first of these was fixed by
20507534d4
This commit fixes another case where we also need to explicitly enable
predictive prefetch, when the pool is initially created.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#8577
UNMAP/TRIM support is a frequently-requested feature to help
prevent performance from degrading on SSDs and on various other
SAN-like storage back-ends. By issuing UNMAP/TRIM commands for
sectors which are no longer allocated the underlying device can
often more efficiently manage itself.
This TRIM implementation is modeled on the `zpool initialize`
feature which writes a pattern to all unallocated space in the
pool. The new `zpool trim` command uses the same vdev_xlate()
code to calculate what sectors are unallocated, the same per-
vdev TRIM thread model and locking, and the same basic CLI for
a consistent user experience. The core difference is that
instead of writing a pattern it will issue UNMAP/TRIM commands
for those extents.
The zio pipeline was updated to accommodate this by adding a new
ZIO_TYPE_TRIM type and associated spa taskq. This new type makes
is straight forward to add the platform specific TRIM/UNMAP calls
to vdev_disk.c and vdev_file.c. These new ZIO_TYPE_TRIM zios are
handled largely the same way as ZIO_TYPE_READs or ZIO_TYPE_WRITEs.
This makes it possible to largely avoid changing the pipieline,
one exception is that TRIM zio's may exceed the 16M block size
limit since they contain no data.
In addition to the manual `zpool trim` command, a background
automatic TRIM was added and is controlled by the 'autotrim'
property. It relies on the exact same infrastructure as the
manual TRIM. However, instead of relying on the extents in a
metaslab's ms_allocatable range tree, a ms_trim tree is kept
per metaslab. When 'autotrim=on', ranges added back to the
ms_allocatable tree are also added to the ms_free tree. The
ms_free tree is then periodically consumed by an autotrim
thread which systematically walks a top level vdev's metaslabs.
Since the automatic TRIM will skip ranges it considers too small
there is value in occasionally running a full `zpool trim`. This
may occur when the freed blocks are small and not enough time
was allowed to aggregate them. An automatic TRIM and a manual
`zpool trim` may be run concurrently, in which case the automatic
TRIM will yield to the manual TRIM.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Contributions-by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Contributions-by: Tim Chase <tim@chase2k.com>
Contributions-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#8419Closes#598
Added missing remove of detachable VDEV from txg's DTL list
to avoid use-after-free for the split VDEV
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Signed-off-by: Roman Strashkin <roman.strashkin@nexenta.com>
Closes#5565Closes#7856
When Multihost is enabled, and a pool is imported, uberblock writes
include ub_mmp_delay to allow an importing node to calculate the
duration of an activity test. This value, is not enough information.
If zfs_multihost_fail_intervals > 0 on the node with the pool imported,
the safe minimum duration of the activity test is well defined, but does
not depend on ub_mmp_delay:
zfs_multihost_fail_intervals * zfs_multihost_interval
and if zfs_multihost_fail_intervals == 0 on that node, there is no such
well defined safe duration, but the importing host cannot tell whether
mmp_delay is high due to I/O delays, or due to a very large
zfs_multihost_interval setting on the host which last imported the pool.
As a result, it may use a far longer period for the activity test than
is necessary.
This patch renames ub_mmp_sequence to ub_mmp_config and uses it to
record the zfs_multihost_interval and zfs_multihost_fail_intervals
values, as well as the mmp sequence. This allows a shorter activity
test duration to be calculated by the importing host in most situations.
These values are also added to the multihost_history kstat records.
It calculates the activity test duration differently depending on
whether the new fields are present or not; for importing pools with
only ub_mmp_delay, it uses
(zfs_multihost_interval + ub_mmp_delay) * zfs_multihost_import_intervals
Which results in an activity test duration less sensitive to the leaf
count.
In addition, it makes a few other improvements:
* It updates the "sequence" part of ub_mmp_config when MMP writes
in between syncs occur. This allows an importing host to detect MMP
on the remote host sooner, when the pool is idle, as it is not limited
to the granularity of ub_timestamp (1 second).
* It issues writes immediately when zfs_multihost_interval is changed
so remote hosts see the updated value as soon as possible.
* It fixes a bug where setting zfs_multihost_fail_intervals = 1 results
in immediate pool suspension.
* Update tests to verify activity check duration is based on recorded
tunable values, not tunable values on importing host.
* Update tests to verify the expected number of uberblocks have valid
MMP fields - fail_intervals, mmp_interval, mmp_seq (sequence number),
that sequence number is incrementing, and that uberblock values match
tunable settings.
Reviewed-by: Andreas Dilger <andreas.dilger@whamcloud.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#7842
Currently, there is an issue in the raw receive code where
raw receives are allowed to happen on top of previously
non-raw received datasets. This is a problem because the
source-side dataset doesn't know about how the blocks on
the destination were encrypted. As a result, any MAC in
the objset's checksum-of-MACs tree that is a parent of both
blocks encrypted on the source and blocks encrypted by the
destination will be incorrect. This will result in
authentication errors when we decrypt the dataset.
This patch fixes this issue by adding a new check to the
raw receive code. The code now maintains an "IVset guid",
which acts as an identifier for the set of IVs used to
encrypt a given snapshot. When a snapshot is raw received,
the destination snapshot will take this value from the
DRR_BEGIN payload. Non-raw receives and normal "zfs snap"
operations will cause ZFS to generate a new IVset guid.
When a raw incremental stream is received, ZFS will check
that the "from" IVset guid in the stream matches that of
the "from" destination snapshot. If they do not match, the
code will error out the receive, preventing the problem.
This patch requires an on-disk format change to add the
IVset guids to snapshots and bookmarks. As a result, this
patch has errata handling and a tunable to help affected
users resolve the issue with as little interruption as
possible.
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#8308
The point of this refactoring is to break the high-level conceptual
steps of spa_sync() to their own helper functions. In general large
functions can enhance readability if structured well, but in this
case the amount of conceptual steps taken could use the help of
helper functions.
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8293
Adds a new lock for serializing operations on zthrs.
The commit also includes some code cleanup and
refactoring.
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Tom Caputi <tcaputi@datto.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#8229
PROBLEM
========
When invoking "zpool initialize" on a pool the command will
create a thread to initialize each disk. Unfortunately, it does
this serially across many transaction groups which can result
in commands taking a long time to return to the user and may
appear hung. The same thing is true when trying to suspend/cancel
the operation.
SOLUTION
=========
This change refactors the way we invoke the initialize interface
to ensure we can start or stop the intialization in just a few
transaction groups.
When stopping or cancelling a vdev initialization perform it
in two phases. First signal each vdev initialization thread
that it should exit, then after all threads have been signaled
wait for them to exit.
On a pool with 40 leaf vdevs this reduces the vdev initialize
stop/cancel time from ~10 minutes to under a second. The reason
for this is spa_vdev_initialize() no longer needs to wait on
multiple full TXGs per leaf vdev being stopped.
This commit additionally adds some missing checks for the passed
"initialize_vdevs" input nvlist. The contents of the user provided
input "initialize_vdevs" nvlist must be validated to ensure all
values are uint64s. This is done in zfs_ioc_pool_initialize() in
order to keep all of these checks in a single location.
Updated the innvl and outnvl comments to match the formatting used
for all other new sytle ioctls.
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes#8230
PROBLEM
========
The first access to a block incurs a performance penalty on some platforms
(e.g. AWS's EBS, VMware VMDKs). Therefore we recommend that volumes are
"thick provisioned", where supported by the platform (VMware). This can
create a large delay in getting a new virtual machines up and running (or
adding storage to an existing Engine). If the thick provision step is
omitted, write performance will be suboptimal until all blocks on the LUN
have been written.
SOLUTION
=========
This feature introduces a way to 'initialize' the disks at install or in the
background to make sure we don't incur this first read penalty.
When an entire LUN is added to ZFS, we make all space available immediately,
and allow ZFS to find unallocated space and zero it out. This works with
concurrent writes to arbitrary offsets, ensuring that we don't zero out
something that has been (or is in the middle of being) written. This scheme
can also be applied to existing pools (affecting only free regions on the
vdev). Detailed design:
- new subcommand:zpool initialize [-cs] <pool> [<vdev> ...]
- start, suspend, or cancel initialization
- Creates new open-context thread for each vdev
- Thread iterates through all metaslabs in this vdev
- Each metaslab:
- select a metaslab
- load the metaslab
- mark the metaslab as being zeroed
- walk all free ranges within that metaslab and translate
them to ranges on the leaf vdev
- issue a "zeroing" I/O on the leaf vdev that corresponds to
a free range on the metaslab we're working on
- continue until all free ranges for this metaslab have been
"zeroed"
- reset/unmark the metaslab being zeroed
- if more metaslabs exist, then repeat above tasks.
- if no more metaslabs, then we're done.
- progress for the initialization is stored on-disk in the vdev’s
leaf zap object. The following information is stored:
- the last offset that has been initialized
- the state of the initialization process (i.e. active,
suspended, or canceled)
- the start time for the initialization
- progress is reported via the zpool status command and shows
information for each of the vdevs that are initializing
Porting notes:
- Added zfs_initialize_value module parameter to set the pattern
written by "zpool initialize".
- Added zfs_vdev_{initializing,removal}_{min,max}_active module options.
Authored by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Wren Kennedy <john.kennedy@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: loli10K <ezomori.nozomu@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Signed-off-by: Tim Chase <tim@chase2k.com>
Ported-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://www.illumos.org/issues/9102
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c3963210ebCloses#8230
Currently, if a resilver is triggered for any reason while an
existing one is running, zfs will immediately restart the existing
resilver from the beginning to include the new drive. This causes
problems for system administrators when a drive fails while another
is already resilvering. In this case, the optimal thing to do to
reduce risk of data loss is to wait for the current resilver to end
before immediately replacing the second failed drive, which allows
the system to operate with two incomplete drives for the minimum
amount of time.
This patch introduces the resilver_defer feature that essentially
does this for the admin without forcing them to wait and monitor
the resilver manually. The change requires an on-disk feature
since we must mark drives that are part of a deferred resilver in
the vdev config to ensure that we do not assume they are done
resilvering when an existing resilver completes.
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: @mmaybee
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7732
The vdev_checkpoint_sm_object(), vdev_obsolete_sm_object(), and
vdev_obsolete_counts_are_precise() functions assume that the
only way a zap_lookup() can fail is if the requested entry is
missing. While this is the most common cause, it's not the only
cause. Attemping to access a damaged ZAP will result in other
errors.
The most likely scenario for accessing a damaged ZAP is during
an extreme rewind pool import. Under these conditions the pool
is expected to contain damaged objects and the import code was
updated to handle this gracefully. Getting an ECKSUM error from
these ZAPs after the pool in import a far less likely, therefore
the behavior for call paths was not modified.
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#7809Closes#7921
Since native ZFS encryption was merged, we have been fighting
against a series of bugs that come down to the same problem: Key
mappings (which must be present during all I/O operations) are
created and destroyed based on dataset ownership, but I/Os can
have traditionally been allowed to "leak" into the next txg after
the dataset is disowned.
In the past we have attempted to solve this problem by trying to
ensure that datasets are disowned ater all I/O is finished by
calling txg_wait_synced(), but we have repeatedly found edge cases
that need to be squashed and code paths that might incur a high
number of txg syncs. This patch attempts to resolve this issue
differently, by adding a reference to the key mapping for each txg
it is dirtied in. By doing so, we can remove many of the
unnecessary calls to txg_wait_synced() we have added in the past
and ensure we don't need to deal with this problem in the future.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7949
Authored by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Toomas Soome <tsoome@me.com>
Reviewed by: Sanjay Nadkarni <sanjay.nadkarni@nexenta.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Approved by: Matthew Ahrens <mahrens@delphix.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://illumos.org/issues/9700
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/82f63c3cCloses#7973
Recent changes in the Linux kernel made it necessary to prefix
the refcount_add() function with zfs_ due to a name collision.
To bring the other functions in line with that and to avoid future
collisions, prefix the other refcount functions as well.
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Schumacher <timschumi@gmx.de>
Closes#7963
Added vdev_resilver_needed() check to verify VDEVs are fully
synced, so that after split the new pool will not be corrupted.
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Roman Strashkin <roman.strashkin@nexenta.com>
Closes#7865Closes#7881
Allocation Classes add the ability to have allocation classes in a
pool that are dedicated to serving specific block categories, such
as DDT data, metadata, and small file blocks. A pool can opt-in to
this feature by adding a 'special' or 'dedup' top-level VDEV.
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Alek Pinchuk <apinchuk@datto.com>
Reviewed-by: Håkan Johansson <f96hajo@chalmers.se>
Reviewed-by: Andreas Dilger <andreas.dilger@chamcloud.com>
Reviewed-by: DHE <git@dehacked.net>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Gregor Kopka <gregor@kopka.net>
Reviewed-by: Kash Pande <kash@tripleback.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#5182
The following patch introduces a few statistics on reads and writes
grouped by dataset. These statistics are implemented as kstats
(backed by aggregate sums for performance) and can be retrieved by
using the dataset objset ID number. The motivation for this change is
to provide some preliminary analytics on dataset usage/performance.
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes#7705
This patch fixes a bug where attempting to receive a send stream
with embedded data into an encrypted dataset would not cleanup
that dataset when the error was reached. The check was moved into
dmu_recv_begin_check(), preventing this issue.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes#7650
Overview
========
We parallelize the allocation process by creating the concept of
"allocators". There are a certain number of allocators per metaslab
group, defined by the value of a tunable at pool open time. Each
allocator for a given metaslab group has up to 2 active metaslabs; one
"primary", and one "secondary". The primary and secondary weight mean
the same thing they did in in the pre-allocator world; primary metaslabs
are used for most allocations, secondary metaslabs are used for ditto
blocks being allocated in the same metaslab group. There is also the
CLAIM weight, which has been separated out from the other weights, but
that is less important to understanding the patch. The active metaslabs
for each allocator are moved from their normal place in the metaslab
tree for the group to the back of the tree. This way, they will not be
selected for use by other allocators searching for new metaslabs unless
all the passive metaslabs are unsuitable for allocations. If that does
happen, the allocators will "steal" from each other to ensure that IOs
don't fail until there is truly no space left to perform allocations.
In addition, the alloc queue for each metaslab group has been broken
into a separate queue for each allocator. We don't want to dramatically
increase the number of inflight IOs on low-end systems, because it can
significantly increase txg times. On the other hand, we want to ensure
that there are enough IOs for each allocator to allow for good
coalescing before sending the IOs to the disk. As a result, we take a
compromise path; each allocator's alloc queue max depth starts at a
certain value for every txg. Every time an IO completes, we increase the
max depth. This should hopefully provide a good balance between the two
failure modes, while not dramatically increasing complexity.
We also parallelize the spa_alloc_tree and spa_alloc_lock, which cause
very similar contention when selecting IOs to allocate. This
parallelization uses the same allocator scheme as metaslab selection.
Performance Results
===================
Performance improvements from this change can vary significantly based
on the number of CPUs in the system, whether or not the system has a
NUMA architecture, the speed of the drives, the values for the various
tunables, and the workload being performed. For an fio async sequential
write workload on a 24 core NUMA system with 256 GB of RAM and 8 128 GB
SSDs, there is a roughly 25% performance improvement.
Future Work
===========
Analysis of the performance of the system with this patch applied shows
that a significant new bottleneck is the vdev disk queues, which also
need to be parallelized. Prototyping of this change has occurred, and
there was a performance improvement, but more work needs to be done
before its stability has been verified and it is ready to be upstreamed.
Authored by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Alexander Motin <mav@FreeBSD.org>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Gordon Ross <gwr@nexenta.com>
Ported-by: Paul Dagnelie <pcd@delphix.com>
Signed-off-by: Paul Dagnelie <pcd@delphix.com>
Porting Notes:
* Fix reservation test failures by increasing tolerance.
OpenZFS-issue: https://illumos.org/issues/9112
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/3f3cc3c3Closes#7682
Details about the motivation of this feature and its usage can
be found in this blogpost:
https://sdimitro.github.io/post/zpool-checkpoint/
A lightning talk of this feature can be found here:
https://www.youtube.com/watch?v=fPQA8K40jAM
Implementation details can be found in big block comment of
spa_checkpoint.c
Side-changes that are relevant to this commit but not explained
elsewhere:
* renames members of "struct metaslab trees to be shorter without
losing meaning
* space_map_{alloc,truncate}() accept a block size as a
parameter. The reason is that in the current state all space
maps that we allocate through the DMU use a global tunable
(space_map_blksz) which defauls to 4KB. This is ok for metaslab
space maps in terms of bandwirdth since they are scattered all
over the disk. But for other space maps this default is probably
not what we want. Examples are device removal's vdev_obsolete_sm
or vdev_chedkpoint_sm from this review. Both of these have a
1:1 relationship with each vdev and could benefit from a bigger
block size.
Porting notes:
* The part of dsl_scan_sync() which handles async destroys has
been moved into the new dsl_process_async_destroys() function.
* Remove "VERIFY(!(flags & FWRITE))" in "kernel.c" so zhack can write
to block device backed pools.
* ZTS:
* Fix get_txg() in zpool_sync_001_pos due to "checkpoint_txg".
* Don't use large dd block sizes on /dev/urandom under Linux in
checkpoint_capacity.
* Adopt Delphix-OS's setting of 4 (spa_asize_inflation =
SPA_DVAS_PER_BP + 1) for the checkpoint_capacity test to speed
its attempts to fill the pool
* Create the base and nested pools with sync=disabled to speed up
the "setup" phase.
* Clear labels in test pool between checkpoint tests to avoid
duplicate pool issues.
* The import_rewind_device_replaced test has been marked as "known
to fail" for the reasons listed in its DISCLAIMER.
* New module parameters:
zfs_spa_discard_memory_limit,
zfs_remove_max_bytes_pause (not documented - debugging only)
vdev_max_ms_count (formerly metaslabs_per_vdev)
vdev_min_ms_count
Authored by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Richard Lowe <richlowe@richlowe.net>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/9166
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/7159fdb8Closes#7570
For zio taskq's which have multiple instances (e.g. z_rd_int_0,
z_rd_int_1, etc), each one has a unique name (the _0, _1, _2 suffix).
This makes performance analysis more difficult, because by default,
`perf` includes the thread name (which is the same as the taskq name) in
the stack trace. This means that we get 8 different stacks, all of
which are doing the same thing, but are executed from different taskq's.
We should remove the suffix of the taskq name, so that all the
read-interrupt threads are named z_rd_int.
Note that we already support multiple taskq's with the same name. This
happens when there are multiple pools. In this case the taskq has a
different tq_instance, which shows up in /proc/spl/taskq-all.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes#7646
We want to be able to pass various settings during import/open of a
pool, which are not only related to rewind. Instead of adding a new
policy and duplicate a bunch of code, we should just rename
rewind_policy to a more generic term like load_policy.
For instance, we'd like to set spa->spa_import_flags from the nvlist,
rather from a flags parameter passed to spa_import as in some cases we
want those flags not only for the import case, but also for the open
case. One such flag could be ZFS_IMPORT_MISSING_LOG (as used in zdb)
which would allow zfs to open a pool when logs are missing.
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://illumos.org/issues/9235
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/d2b1e44Closes#7532
Minimal changes required to integrate the SPL sources in to the
ZFS repository build infrastructure and packaging.
Build system and packaging:
* Renamed SPL_* autoconf m4 macros to ZFS_*.
* Removed redundant SPL_* autoconf m4 macros.
* Updated the RPM spec files to remove SPL package dependency.
* The zfs package obsoletes the spl package, and the zfs-kmod
package obsoletes the spl-kmod package.
* The zfs-kmod-devel* packages were updated to add compatibility
symlinks under /usr/src/spl-x.y.z until all dependent packages
can be updated. They will be removed in a future release.
* Updated copy-builtin script for in-kernel builds.
* Updated DKMS package to include the spl.ko.
* Updated stale AUTHORS file to include all contributors.
* Updated stale COPYRIGHT and included the SPL as an exception.
* Renamed README.markdown to README.md
* Renamed OPENSOLARIS.LICENSE to LICENSE.
* Renamed DISCLAIMER to NOTICE.
Required code changes:
* Removed redundant HAVE_SPL macro.
* Removed _BOOT from nvpairs since it doesn't apply for Linux.
* Initial header cleanup (removal of empty headers, refactoring).
* Remove SPL repository clone/build from zimport.sh.
* Use of DEFINE_RATELIMIT_STATE and DEFINE_SPINLOCK removed due
to build issues when forcing C99 compilation.
* Replaced legacy ACCESS_ONCE with READ_ONCE.
* Include needed headers for `current` and `EXPORT_SYMBOL`.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Pavel Zakharov <pavel.zakharov@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
TEST_ZIMPORT_SKIP="yes"
Closes#7556
Add vdev_print_tree() in spa_check_for_missing_logs() when some log
devices are missing to ease debugging
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
OpenZFS-issue: https://illumos.org/issues/9191
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/c5c02e5Closes#7531
Some work has been done lately to improve the debugability of the ZFS pool
load (and import) process. This includes:
7638 Refactor spa_load_impl into several functions
8961 SPA load/import should tell us why it failed
7277 zdb should be able to print zfs_dbgmsg's
To iterate on top of that, there's a few changes that were made to make the
import process more resilient and crash free. One of the first tasks during the
pool load process is to parse a config provided from userland that describes
what devices the pool is composed of. A vdev tree is generated from that config,
and then all the vdevs are opened.
The Meta Object Set (MOS) of the pool is accessed, and several metadata objects
that are necessary to load the pool are read. The exact configuration of the
pool is also stored inside the MOS. Since the configuration provided from
userland is external and might not accurately describe the vdev tree
of the pool at the txg that is being loaded, it cannot be relied upon to safely
operate the pool. For that reason, the configuration in the MOS is read early
on. In the past, the two configurations were compared together and if there was
a mismatch then the load process was aborted and an error was returned.
The latter was a good way to ensure a pool does not get corrupted, however it
made the pool load process needlessly fragile in cases where the vdev
configuration changed or the userland configuration was outdated. Since the MOS
is stored in 3 copies, the configuration provided by userland doesn't have to be
perfect in order to read its contents. Hence, a new approach has been adopted:
The pool is first opened with the untrusted userland configuration just so that
the real configuration can be read from the MOS. The trusted MOS configuration
is then used to generate a new vdev tree and the pool is re-opened.
When the pool is opened with an untrusted configuration, writes are disabled
to avoid accidentally damaging it. During reads, some sanity checks are
performed on block pointers to see if each DVA points to a known vdev;
when the configuration is untrusted, instead of panicking the system if those
checks fail we simply avoid issuing reads to the invalid DVAs.
This new two-step pool load process now allows rewinding pools accross
vdev tree changes such as device replacement, addition, etc. Loading a pool
from an external config file in a clustering environment also becomes much
safer now since the pool will import even if the config is outdated and didn't,
for instance, register a recent device addition.
With this code in place, it became relatively easy to implement a
long-sought-after feature: the ability to import a pool with missing top level
(i.e. non-redundant) devices. Note that since this almost guarantees some loss
of data, this feature is for now restricted to a read-only import.
Porting notes (ZTS):
* Fix 'make dist' target in zpool_import
* The maximum path length allowed by tar is 99 characters. Several
of the new test cases exceeded this limit resulting in them not
being included in the tarball. Shorten the names slightly.
* Set/get tunables using accessor functions.
* Get last synced txg via the "zfs_txg_history" mechanism.
* Clear zinject handlers in cleanup for import_cache_device_replaced
and import_rewind_device_replaced in order that the zpool can be
exported if there is an error.
* Increase FILESIZE to 8G in zfs-test.sh to allow for a larger
ext4 file system to be created on ZFS_DISK2. Also, there's
no need to partition ZFS_DISK2 at all. The partitioning had
already been disabled for multipath devices. Among other things,
the partitioning steals some space from the ext4 file system,
makes it difficult to accurately calculate the paramters to
parted and can make some of the tests fail.
* Increase FS_SIZE and FILE_SIZE in the zpool_import test
configuration now that FILESIZE is larger.
* Write more data in order that device evacuation take lonnger in
a couple tests.
* Use mkdir -p to avoid errors when the directory already exists.
* Remove use of sudo in import_rewind_config_changed.
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/9075
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/619c0123Closes#7459
Currently `zdb` consistently fails to examine non-idle pools as it
fails during the `spa_load()` process. The main problem seems to be
that `spa_load_verify()` fails as can be seen below:
$ sudo zdb -d -G dcenter
zdb: can't open 'dcenter': I/O error
ZFS_DBGMSG(zdb):
spa_open_common: opening dcenter
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c4t11d0s0': best uberblock found for spa dcenter. txg 40824950
spa_load(dcenter): using uberblock with txg=40824950
spa_load(dcenter): UNLOADING
spa_load(dcenter): RELOADING
spa_load(dcenter): LOADING
disk vdev '/dev/dsk/c3t10d0s0': best uberblock found for spa dcenter. txg 40824952
spa_load(dcenter): using uberblock with txg=40824952
spa_load(dcenter): FAILED: spa_load_verify failed [error=5]
spa_load(dcenter): UNLOADING
This change makes `spa_load_verify()` a dryrun when ran from
`zdb`. This is done by creating a global flag in zfs and then setting
it in `zdb`.
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andy Stormont <astormont@racktopsystems.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/8962
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/180ad792Closes#7459
Problem
=======
When we fail to open or import a storage pool, we typically don't
get any additional diagnostic information, just "no pool found" or
"can not import".
While there may be no additional user-consumable information, we should
at least make this situation easier to debug/diagnose for developers
and support. For example, we could start by using `zfs_dbgmsg()`
to log each thing that we try when importing, and which things
failed. E.g. "tried uberblock of txg X from label Y of device Z". Also,
we could log each of the stages that we go through in `spa_load_impl()`.
Solution
========
Following the cleanup to `spa_load_impl()`, debug messages have been
added to every point of failure in that function. Additionally,
debug messages have been added to strategic places, such as
`vdev_disk_open()`.
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/8961
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/418079e0Closes#7459
Commit 7fab6361 inadvertently disabled the MMP test cases by creating
and not removing an /etc/hostid file in the new zpool_split_props test
case. When the file exists the ZTS skips the entire MMP test group
rather than modify what may be a system which is already configured.
Update the test case to remove the file.
Additionally, because the MMP tests were disabled a regression slipped
in as part of commit 9eb7b46ed0. Fix it.
Reviewed-by: Tim Chase <tim@chase2k.com>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#7514
Authored by: Pavel Zakharov <pavel.zakharov@delphix.com>
Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Andrew Stormont <andyjstormont@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tim Chase <tim@chase2k.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Ported-by: Giuseppe Di Natale <dinatale2@llnl.gov>
OpenZFS-issue: https://www.illumos.org/issues/7638
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/1fd3785ff6Closes#7437
The timeline of the race condition is the following:
[1] Thread A is about to finish condesing the first vdev in
spa_condense_indirect_thread(), so it calls the
spa_condense_indirect_complete_sync() sync task which sets
the spa_condensing_indirect field to NULL. Waiting for the
sync task to finish, thread A sleeps until the txg is done.
When this happens, thread A will acquire spa_async_lock and
set spa_condense_thread to NULL.
[2] While thread A waits for the txg to finish, thread B which is
running spa_sync() checks whether it should condense the
second vdev in vdev_indirect_should_condense() by checking the
spa_condensing_indirect field which was set to NULL by
spa_condense_indirect_thread() from thread A. So it goes on
and tries to spawn a new condensing thread in
spa_condense_indirect_start_sync() and the aforementioned
assertions fails because thread A has not set spa_condense_thread
to NULL (which is basically the last thing it does before returning).
The main issue here is that we rely on both spa_condensing_indirect
and spa_condense_thread to signify whether a condensing thread is
running. Ideally we would only use one throughout the codebase. In
addition, for managing spa_condense_thread we currently use
spa_async_lock which basically tights condensing to scrubing when
it comes to pausing and resuming those actions during spa export.
This commit introduces the ZTHR infrastructure, which is basically
threads created during spa_load()/spa_create() and exist until we
export or destroy the pool. ZTHRs sleep the majority of the time,
until they are notified to wake up and do some predefined type of work.
In the context of the current bug, a zthr to does the condensing of
indirect mappings replacing the older code that used bare kthreads.
When a pool is created, the condensing zthr is spawned but sleeps
right away, until it is awaken by a signal from spa_sync(). If an
existing pool is loaded, the condensing zthr looks if there is
anything to condense before going to sleep, in case we were condensing
mappings in the pool before it got exported.
The benefits of this solution are the following:
- The current bug is fixed
- spa_condensing_indirect is the sole indicator of whether we are
currently condensing or not
- condensing is more decoupled from the spa_async_thread related
functionality.
As a final note, this commit also sets up the path on upstreaming
other features that use the ZTHR code like zpool checkpoint and
fast clone deletion.
Authored by: Serapheim Dimitropoulos <serapheim@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Reviewed by: Pavel Zakharov <pavel.zakharov@delphix.com>
Approved by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Ported-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/9079
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/3dc606eeCloses#6900
Mirrors are supposed to provide redundancy in the face of whole-disk
failure and silent damage (e.g. some data on disk is not right, but ZFS
hasn't detected the whole device as being broken). However, the current
device removal implementation bypasses some of the mirror's redundancy.
Note that in no case is incorrect data returned, but we might get a
checksum error when we should have been able to find the right data.
There are two underlying problems:
1. When we remove a mirror device, we only read one side of the mirror.
Since we can't verify the checksum, this side may be silently bad, but
the good data is on the other side of the mirror (which we didn't read).
This can cause the removal to "bake in" the busted data – all copies of
the data in the new location are the same, busted version, while we left
the good version behind.
The fix for this is to read and copy both sides of the mirror. If the
old and new vdevs are mirrors, we will read both sides of the old
mirror, and write each copy to the corresponding side of the new mirror.
(If the old and new vdevs have a different number of children, we will
do this as best as possible.) Even though we aren't verifying checksums,
this ensures that as long as there's a good copy of the data, we'll have
a good copy after the removal, even if there's silent damage to one side
of the mirror. If we're removing a mirror that has some silent damage,
we'll have exactly the same damage in the new location (assuming that
the new location is also a mirror).
2. When we read from an indirect vdev that points to a mirror vdev, we
only consider one copy of the data. This can lead to reduced effective
redundancy, because we might read a bad copy of the data from one side
of the mirror, and not retry the other, good side of the mirror.
Note that the problem is not with the removal process, but rather after
the removal has completed (having copied correct data to both sides of
the mirror), if one side of the new mirror is silently damaged, we
encounter the problem when reading the relocated data via the indirect
vdev. Also note that the problem doesn't occur when ZFS knows that one
side of the mirror is bad, e.g. when a disk entirely fails or is
offlined.
The impact is that reads (from indirect vdevs that point to mirrors) may
return a checksum error even though the good data exists on one side of
the mirror, and scrub doesn't repair all data on the mirror (if some of
it is pointed to via an indirect vdev).
The fix for this is complicated by "split blocks" - one logical block
may be split into two (or more) pieces with each piece moved to a
different new location. In this case we need to read all versions of
each split (one from each side of the mirror), and figure out which
combination of versions results in the correct checksum, and then repair
the incorrect versions.
This ensures that we supply the same redundancy whether you use device
removal or not. For example, if a mirror has small silent errors on all
of its children, we can still reconstruct the correct data, as long as
those errors are at sufficiently-separated offsets (specifically,
separated by the largest block size - default of 128KB, but up to 16MB).
Porting notes:
* A new indirect vdev check was moved from dsl_scan_needs_resilver_cb()
to dsl_scan_needs_resilver(), which was added to ZoL as part of the
sequential scrub work.
* Passed NULL for zfs_ereport_post_checksum()'s zbookmark_phys_t
parameter. The extra parameter is unique to ZoL.
* When posting indirect checksum errors the ABD can be passed directly,
zfs_ereport_post_checksum() is not yet ABD-aware in OpenZFS.
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Ported-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://illumos.org/issues/9290
OpenZFS-commit: https://github.com/openzfs/openzfs/pull/591Closes#6900
OpenZFS 7614 - zfs device evacuation/removal
OpenZFS 9064 - remove_mirror should wait for device removal to complete
This project allows top-level vdevs to be removed from the storage pool
with "zpool remove", reducing the total amount of storage in the pool.
This operation copies all allocated regions of the device to be removed
onto other devices, recording the mapping from old to new location.
After the removal is complete, read and free operations to the removed
(now "indirect") vdev must be remapped and performed at the new location
on disk. The indirect mapping table is kept in memory whenever the pool
is loaded, so there is minimal performance overhead when doing operations
on the indirect vdev.
The size of the in-memory mapping table will be reduced when its entries
become "obsolete" because they are no longer used by any block pointers
in the pool. An entry becomes obsolete when all the blocks that use
it are freed. An entry can also become obsolete when all the snapshots
that reference it are deleted, and the block pointers that reference it
have been "remapped" in all filesystems/zvols (and clones). Whenever an
indirect block is written, all the block pointers in it will be "remapped"
to their new (concrete) locations if possible. This process can be
accelerated by using the "zfs remap" command to proactively rewrite all
indirect blocks that reference indirect (removed) vdevs.
Note that when a device is removed, we do not verify the checksum of
the data that is copied. This makes the process much faster, but if it
were used on redundant vdevs (i.e. mirror or raidz vdevs), it would be
possible to copy the wrong data, when we have the correct data on e.g.
the other side of the mirror.
At the moment, only mirrors and simple top-level vdevs can be removed
and no removal is allowed if any of the top-level vdevs are raidz.
Porting Notes:
* Avoid zero-sized kmem_alloc() in vdev_compact_children().
The device evacuation code adds a dependency that
vdev_compact_children() be able to properly empty the vdev_child
array by setting it to NULL and zeroing vdev_children. Under Linux,
kmem_alloc() and related functions return a sentinel pointer rather
than NULL for zero-sized allocations.
* Remove comment regarding "mpt" driver where zfs_remove_max_segment
is initialized to SPA_MAXBLOCKSIZE.
Change zfs_condense_indirect_commit_entry_delay_ticks to
zfs_condense_indirect_commit_entry_delay_ms for consistency with
most other tunables in which delays are specified in ms.
* ZTS changes:
Use set_tunable rather than mdb
Use zpool sync as appropriate
Use sync_pool instead of sync
Kill jobs during test_removal_with_operation to allow unmount/export
Don't add non-disk names such as "mirror" or "raidz" to $DISKS
Use $TEST_BASE_DIR instead of /tmp
Increase HZ from 100 to 1000 which is more common on Linux
removal_multiple_indirection.ksh
Reduce iterations in order to not time out on the code
coverage builders.
removal_resume_export:
Functionally, the test case is correct but there exists a race
where the kernel thread hasn't been fully started yet and is
not visible. Wait for up to 1 second for the removal thread
to be started before giving up on it. Also, increase the
amount of data copied in order that the removal not finish
before the export has a chance to fail.
* MMP compatibility, the concept of concrete versus non-concrete devices
has slightly changed the semantics of vdev_writeable(). Update
mmp_random_leaf_impl() accordingly.
* Updated dbuf_remap() to handle the org.zfsonlinux:large_dnode pool
feature which is not supported by OpenZFS.
* Added support for new vdev removal tracepoints.
* Test cases removal_with_zdb and removal_condense_export have been
intentionally disabled. When run manually they pass as intended,
but when running in the automated test environment they produce
unreliable results on the latest Fedora release.
They may work better once the upstream pool import refectoring is
merged into ZoL at which point they will be re-enabled.
Authored by: Matthew Ahrens <mahrens@delphix.com>
Reviewed-by: Alex Reece <alex@delphix.com>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: John Kennedy <john.kennedy@delphix.com>
Reviewed-by: Prakash Surya <prakash.surya@delphix.com>
Reviewed by: Richard Laager <rlaager@wiktel.com>
Reviewed by: Tim Chase <tim@chase2k.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Garrett D'Amore <garrett@damore.org>
Ported-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Tim Chase <tim@chase2k.com>
OpenZFS-issue: https://www.illumos.org/issues/7614
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/f539f1ebCloses#6900
When an MMP write is skipped, or fails, and time since
mts->mmp_last_write is already greater than mts->mmp_delay, increase
mts->mmp_delay. The original code only updated mts->mmp_delay when a
write succeeded, but this results in the write(s) after delays and
failed write(s) reporting an ub_mmp_delay which is too low.
Update mmp_last_write and mmp_delay if a txg sync was successful. At
least one uberblock was written, thus extending the time we can be sure
the pool will not be imported by another host.
Do not allow mmp_delay to go below (MSEC2NSEC(zfs_multihost_interval) /
vdev_count_leaves()) so that a period of frequent successful MMP writes,
e.g. due to frequent txg syncs, does not result in an import activity
check so short it is not reliable based on mmp thread writes alone.
Remove unnecessary local variable, start. We do not use the start time
of the loop iteration.
Add a debug message in spa_activity_check() to allow verification of the
import_delay value and to prove the activity check occurred.
Alter the tests that import pools and attempt to detect an activity
check. Calculate the expected duration of spa_activity_check() based on
module parameters at the time the import is performed, rather than a
fixed time set in mmp.cfg. The fixed time may be wrong. Also, use the
default zfs_multihost_interval value so the activity check is longer and
easier to recognize.
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes#7330
