zfs/man/man8
Matthew Ahrens f1512ee61e Illumos 5027 - zfs large block support
5027 zfs large block support
Reviewed by: Alek Pinchuk <pinchuk.alek@gmail.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <josef.sipek@nexenta.com>
Reviewed by: Richard Elling <richard.elling@richardelling.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/5027
  https://github.com/illumos/illumos-gate/commit/b515258

Porting Notes:

* Included in this patch is a tiny ISP2() cleanup in zio_init() from
Illumos 5255.

* Unlike the upstream Illumos commit this patch does not impose an
arbitrary 128K block size limit on volumes.  Volumes, like filesystems,
are limited by the zfs_max_recordsize=1M module option.

* By default the maximum record size is limited to 1M by the module
option zfs_max_recordsize.  This value may be safely increased up to
16M which is the largest block size supported by the on-disk format.
At the moment, 1M blocks clearly offer a significant performance
improvement but the benefits of going beyond this for the majority
of workloads are less clear.

* The illumos version of this patch increased DMU_MAX_ACCESS to 32M.
This was determined not to be large enough when using 16M blocks
because the zfs_make_xattrdir() function will fail (EFBIG) when
assigning a TX.  This was immediately observed under Linux because
all newly created files must have a security xattr created and
that was failing.  Therefore, we've set DMU_MAX_ACCESS to 64M.

* On 32-bit platforms a hard limit of 1M is set for blocks due
to the limited virtual address space.  We should be able to relax
this one the ABD patches are merged.

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #354
2015-05-11 12:23:16 -07:00
..
.gitignore Initial implementation of zed (ZFS Event Daemon) 2014-04-02 13:10:03 -07:00
Makefile.am Initial implementation of zed (ZFS Event Daemon) 2014-04-02 13:10:03 -07:00
fsck.zfs.8 Fix NAME section of manpages zhack and fsck.zfs. 2014-03-10 09:19:17 -07:00
mount.zfs.8 Add full SELinux support 2013-12-19 10:37:31 -08:00
vdev_id.8 vdev_id support for device link aliases 2012-12-03 14:04:47 -08:00
zdb.8 Document environment variables for zdb, zfs, zinject and zpool. 2014-09-18 15:01:03 -07:00
zed.8.in Refer to ZED's scripts as ZEDLETs 2014-09-25 13:54:17 -07:00
zfs.8 Illumos 5027 - zfs large block support 2015-05-11 12:23:16 -07:00
zinject.8 Document environment variables for zdb, zfs, zinject and zpool. 2014-09-18 15:01:03 -07:00
zpool.8 Add the '-a' option to 'zpool export' 2015-05-04 10:17:08 -07:00
zstreamdump.8 Add zstreamdump(8) command to examine ZFS send streams. 2012-09-02 14:54:27 -07:00