mirror_zfs/cmd
Matthew Ahrens bee5738f77 make zil max block size tunable
We've observed that on some highly fragmented pools, most metaslab
allocations are small (~2-8KB), but there are some large, 128K
allocations.  The large allocations are for ZIL blocks.  If there is a
lot of fragmentation, the large allocations can be hard to satisfy.

The most common impact of this is that we need to check (and thus load)
lots of metaslabs from the ZIL allocation code path, causing sync writes
to wait for metaslabs to load, which can take a second or more.  In the
worst case, we may not be able to satisfy the allocation, in which case
the ZIL will resort to txg_wait_synced() to ensure the change is on
disk.

To provide a workaround for this, this change adds a tunable that can
reduce the size of ZIL blocks.

External-issue: DLPX-61719
Reviewed-by: George Wilson <george.wilson@delphix.com>
Reviewed-by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matthew Ahrens <mahrens@delphix.com>
Closes #8865
2020-01-22 13:48:56 -08:00
..
arc_summary arc_summary: prefer python3 version and install when there is no python 2019-06-11 10:45:02 -07:00
arcstat pyzfs: python3 support (build system) 2019-01-06 10:39:41 -08:00
dbufstat pyzfs: python3 support (build system) 2019-01-06 10:39:41 -08:00
fsck_zfs Add /sbin/fsck.zfs helper 2013-01-09 16:54:58 -08:00
mount_zfs Add libzutil for libzfs or libzpool consumers 2018-11-05 11:22:33 -08:00
raidz_test Support -fsanitize=address with --enable-asan 2018-01-10 10:49:27 -08:00
vdev_id Add enclosure_symlinks option to vdev_id 2018-12-14 17:27:49 -08:00
zdb MMP interval and fail_intervals in uberblock 2019-03-21 12:47:57 -07:00
zed zed crashes when devid not present 2019-09-25 11:27:50 -07:00
zfs Let zfs mount all tolerate in-progress mounts 2019-09-25 11:27:48 -07:00
zgenhostid Add zgenhostid utility script 2017-07-25 13:22:03 -04:00
zhack Add libzutil for libzfs or libzpool consumers 2018-11-05 11:22:33 -08:00
zinject Cleanup nits from ab7615d92 2019-04-14 11:03:06 -07:00
zpool Fix zpool subcommands error message with some unsupported options 2019-09-25 11:27:51 -07:00
zstreamdump zstreamdump: add per-record-type counters and an overhead counter 2019-09-25 11:27:48 -07:00
ztest make zil max block size tunable 2020-01-22 13:48:56 -08:00
zvol_id Fedora 28: Fix misc bounds check compiler warnings 2018-04-04 10:16:47 -07:00
zvol_wait zvol_wait script should ignore partially received zvols 2019-09-25 11:27:51 -07:00
Makefile.am New service that waits on zvol links to be created 2019-09-25 11:27:51 -07:00