From 27b293be8af2cd83ae26ef50e6ee12600dce1d5b Mon Sep 17 00:00:00 2001 From: Tim Chase Date: Wed, 4 Jun 2014 07:23:31 -0500 Subject: Expand the description of scan-related and other parameters. Document that the scan-related parameters are, in fact, applicable only to scrub and/or resilver operations as appropriate. Expand a few of the prefetch-related descriptions. Add clarification to other module parameters. Signed-off-by: Tim Chase Signed-off-by: Brian Behlendorf Closes #2361 --- man/man5/zfs-module-parameters.5 | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) (limited to 'man/man5/zfs-module-parameters.5') diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 815c856c0..586712940 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -189,7 +189,7 @@ Default value: 24 \fBzfetch_array_rd_sz\fR (ulong) .ad .RS 12n -Number of bytes in a array_read +If prefetching is enabled, disable prefetching for reads larger than this size. .sp Default value: \fB1,048,576\fR. .RE @@ -200,7 +200,7 @@ Default value: \fB1,048,576\fR. \fBzfetch_block_cap\fR (uint) .ad .RS 12n -Max number of blocks to fetch at a time +Max number of blocks to prefetch at a time .sp Default value: \fB256\fR. .RE @@ -211,7 +211,7 @@ Default value: \fB256\fR. \fBzfetch_max_streams\fR (uint) .ad .RS 12n -Max number of streams per zfetch +Max number of streams per zfetch (prefetch streams per file). .sp Default value: \fB8\fR. .RE @@ -222,7 +222,7 @@ Default value: \fB8\fR. \fBzfetch_min_sec_reap\fR (uint) .ad .RS 12n -Min time before stream reclaim +Min time before an active prefetch stream can be reclaimed .sp Default value: \fB2\fR. .RE @@ -343,7 +343,7 @@ Default value: \fB5\fR. \fBzfs_autoimport_disable\fR (int) .ad .RS 12n -Disable pool import at module load +Disable pool import at module load by ignoring the cache file (typically \fB/etc/zfs/zpool.cache\fR). .sp Use \fB1\fR for yes and \fB0\fR for no (default). .RE @@ -846,7 +846,9 @@ Use \fB1\fR for yes and \fB0\fR for no (default). \fBzfs_resilver_delay\fR (int) .ad .RS 12n -Number of ticks to delay resilver +Number of ticks to delay prior to issuing a resilver I/O operation when +a non-resilver or non-scrub I/O operation has occurred within the past +\fBzfs_scan_idle\fR ticks. .sp Default value: \fB2\fR. .RE @@ -868,7 +870,10 @@ Default value: \fB3,000\fR. \fBzfs_scan_idle\fR (int) .ad .RS 12n -Idle window in clock ticks +Idle window in clock ticks. During a scrub or a resilver, if +a non-scrub or non-resilver I/O operation has occurred during this +window, the next scrub or resilver operation is delayed by, respectively +\fBzfs_scrub_delay\fR or \fBzfs_resilver_delay\fR ticks. .sp Default value: \fB50\fR. .RE @@ -890,7 +895,9 @@ Default value: \fB1,000\fR. \fBzfs_scrub_delay\fR (int) .ad .RS 12n -Number of ticks to delay scrub +Number of ticks to delay prior to issuing a scrub I/O operation when +a non-scrub or non-resilver I/O operation has occurred within the past +\fBzfs_scan_idle\fR ticks. .sp Default value: \fB4\fR. .RE @@ -945,7 +952,7 @@ Default value: \fB2\fR. \fBzfs_top_maxinflight\fR (int) .ad .RS 12n -Max I/Os per top-level +Max I/Os per top-level vdev during scrub or resilver operations. .sp Default value: \fB32\fR. .RE -- cgit v1.2.3