== Motivation and Context
The current implementation of 'sharenfs' and 'sharesmb' relies on
the use of the sharetab file. The use of this file is os-specific
and not required by linux or freebsd. Currently the code must
maintain updates to this file which adds complexity and presents
a significant performance impact when sharing many datasets. In
addition, concurrently running 'zfs sharenfs' command results in
missing entries in the sharetab file leading to unexpected failures.
== Description
This change removes the sharetab logic from the linux and freebsd
implementation of 'sharenfs' and 'sharesmb'. It still preserves an
os-specific library which contains the logic required for sharing
NFS or SMB. The following entry points exist in the vastly simplified
libshare library:
- sa_enable_share -- shares a dataset but may not commit the change
- sa_disable_share -- unshares a dataset but may not commit the change
- sa_is_shared -- determine if a dataset is shared
- sa_commit_share -- notify NFS/SMB subsystem to commit the shares
- sa_validate_shareopts -- determine if sharing options are valid
The sa_commit_share entry point is provided as a performance enhancement
and is not required. The sa_enable_share/sa_disable_share may commit
the share as part of the implementation. Libshare provides a framework
for both NFS and SMB but some operating systems may not fully support
these protocols or all features of the protocol.
NFS Operation:
For linux, libshare updates /etc/exports.d/zfs.exports to add
and remove shares and then commits the changes by invoking
'exportfs -r'. This file, is automatically read by the kernel NFS
implementation which makes for better integration with the NFS systemd
service. For FreeBSD, libshare updates /etc/zfs/exports to add and
remove shares and then commits the changes by sending a SIGHUP to
mountd.
SMB Operation:
For linux, libshare adds and removes files in /var/lib/samba/usershares
by calling the 'net' command directly. There is no need to commit the
changes. FreeBSD does not support SMB.
== Performance Results
To test sharing performance we created a pool with an increasing number
of datasets and invoked various zfs actions that would enable and
disable sharing. The performance testing was limited to NFS sharing.
The following tests were performed on an 8 vCPU system with 128GB and
a pool comprised of 4 50GB SSDs:
Scale testing:
- Share all filesystems in parallel -- zfs sharenfs=on <dataset> &
- Unshare all filesystems in parallel -- zfs sharenfs=off <dataset> &
Functional testing:
- share each filesystem serially -- zfs share -a
- unshare each filesystem serially -- zfs unshare -a
- reset sharenfs property and unshare -- zfs inherit -r sharenfs <pool>
For 'zfs sharenfs=on' scale testing we saw an average reduction in time
of 89.43% and for 'zfs sharenfs=off' we saw an average reduction in time
of 83.36%.
Functional testing also shows a huge improvement:
- zfs share -- 97.97% reduction in time
- zfs unshare -- 96.47% reduction in time
- zfs inhert -r sharenfs -- 99.01% reduction in time
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Bryant G. Ly <bryangly@gmail.com>
Signed-off-by: George Wilson <gwilson@delphix.com>
External-Issue: DLPX-68690
Closes#1603Closes#7692Closes#7943Closes#10300
When a system boots the zfs-mount.service and the
zfs-share.service can start simultaneously. What may be
unclear is that sharing a filesystem will first mount
the filesystem if it's not already mounted. This means
that both service can race to mount the same fileystem.
This race can result in a SEGFAULT or EBUSY conditions.
This change explicitly defines the start ordering between the
two services such that the zfs-mount.service is solely
responsible for mounting filesystems eliminating the race
between "zfs mount -a" and "zfs share -a" commands.
Reviewed-by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Wilson <george.wilson@delphix.com>
Closes#9083
ZFS NFS shares mounted on a client with NFSv3 and with open
locks will fail to reclaim those locks after a server reboot.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Don Brady <don.brady@delphix.com>
Closes#8398
Some redundancy is present in the systemd dependencies, as
noticed in PR#6764. Existing setups might rely on these quirks,
so these cleanups have been moved to the development branch.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Antonio Russo <antonio.e.russo@gmail.com>
Closes#6822
Reviewed-by: George Melikov <mail@gmelikov.ru>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
Closes#6599
Use the system /bin directory rather than the package install
@bindir@. This allows --prefix=/usr/local to work as intended.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: loli10K <ezomori.nozomu@gmail.com>
Closes#5559
* Disable zfs-import-scan.service by default. This ensures that
pools will not be automatically imported unless they appear in
the cache file. When this service is explicitly enabled pools
will be imported with the "cachefile=none" property set. This
prevents the creation of, or update to, an existing cache file.
$ systemctl list-unit-files | grep zfs
zfs-import-cache.service enabled
zfs-import-scan.service disabled
zfs-mount.service enabled
zfs-share.service enabled
zfs-zed.service enabled
zfs.target enabled
* Change services to dynamic from static by adding an [Install]
section and adding 'WantedBy' tags in favor of 'Requires' tags.
This allows for easier customization of the boot behavior.
* Start the zfs-import-cache.service after the root pivot so
the cache file is available in the standard location.
* Start the zfs-mount.service after the systemd-remount-fs.service
to ensure the root fs is writeable and the ZFS filesystems can
create their mount points.
* Change the default behavior to only load the ZFS kernel modules
in zfs-import-*.service or when blkid(8) detects a pool. Users
who wish to unconditionally load the kernel modules must uncomment
the list of modules in /lib/modules-load.d/zfs.conf.
Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4325Closes#4496Closes#4658Closes#4699
Debian based systems use nfs-kernel-server as the service name.
List both nfs-server.service and nfs-kernel-server.service so
this service will work on multiple distributions.
Signed-off-by: Grischa Zengel <github.zfsonlinux@zengel.info>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#4350
The systemd script zfs-share.service does 'zfs share -a' to share
any required datasets. Unfortunately, /etc/dfs/sharetab is stale
from the previous boot. Delete it before we share.
Signed-off-by: Dan Swartzendruber <dswartz@druber.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2883
The zfs-share.service rule needs to be modified to ensure that it
does not execute before zfs-mount.service.
Signed-off-by: Dan Swartzendruber <dswartz@druber.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ralf Ertzinger <ralf@skytale.net>
Closes#2893
This adds systemd unit files replacing the functionality offered by
the SysV init script found in etc/init.d.
It has been developed and tested on Fedora 19, Fedora 20
and openSuSE 13.1.
Four unit files and one target are offered.
zfs-import-cache.service:
Import pools from /etc/zfs/zpool.cache. This unit will wait for
udev to settle.
zfs-import-scan.service:
Import pools by scanning /dev/disk/by-id for zvols. This unit will
only run if /etc/zfs/zpool.cache is not present. This unit will wait
for udev to settle
zfs-mount.service:
Mount ZFS native filesystems. It contains a dependency to be loaded
before local-fs.target.
zfs-share.service:
Share NFS/SMB filesystems. This unit contains a dependency that
will cause it to be restarted whenever the smb or nfs-server unit
is restarted, restoring the shares added.
zfs.target:
This target pulls in the other units in order to start ZFS. It's
the only unit that can be enabled/disabled, all other services
are static and pulled in by dependencies. It will honour zfs=off
and zfs=no options on the kernel command line.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#2108
