mirror_zfs/man
Brian Behlendorf c0aea7cf4e Increase default zfs_scan_vdev_limit to 16MB
For HDD based pools the default zfs_scan_vdev_limit of 4M
per-vdev can significantly limit the maximum scrub performance.
Increasing the default to 16M can double the scrub speed from
80 MB/s per disk to 160 MB/s per disk.

This does increase the memory footprint during scrub/resilver
but given the performance win this is a reasonable trade off.
Memory usage is capped at 1/4 of arc_c_max.  Note that number
of outstanding I/Os has not changed and is still limited by
zfs_vdev_scrub_max_active.

Reviewed-by: Akash B <akash-b@hpe.com>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #14428
2023-01-27 10:01:13 -08:00
..
man1 Update arc_summary and arcstat outputs 2023-01-05 09:29:13 -08:00
man4 Increase default zfs_scan_vdev_limit to 16MB 2023-01-27 10:01:13 -08:00
man5 Consistentify miscellaneous style on remaining manpages 2021-06-09 14:35:53 -07:00
man7 Configure zed's diagnosis engine with vdev properties 2023-01-23 13:14:25 -08:00
man8 Use setproctitle to report progress of zfs send 2023-01-17 10:17:35 -08:00
Makefile.am Add Linux namespace delegation support 2022-06-10 09:51:46 -07:00