From 0dfc732416922e1dd59028fa900d38d04dceaa12 Mon Sep 17 00:00:00 2001 From: Alexey Smirnoff Date: Sat, 30 Aug 2014 09:13:26 +0700 Subject: [PATCH] Change the default 'zfs_dedup_prefetch' value to '0' This gives a huge performance improvement in operations with deduped datasets especially when the bottleneck is the amount of ram available for zfs. Signed-off-by: Brian Behlendorf Closes #2639 --- man/man5/zfs-module-parameters.5 | 2 +- module/zfs/ddt.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5 index 3d7093b73..eff5344eb 100644 --- a/man/man5/zfs-module-parameters.5 +++ b/man/man5/zfs-module-parameters.5 @@ -503,7 +503,7 @@ Default value: \fB1,000,000\fR. .RS 12n Enable prefetching dedup-ed blks .sp -Use \fB1\fR for yes (default) and \fB0\fR to disable. +Use \fB1\fR for yes and \fB0\fR to disable (default). .RE .sp diff --git a/module/zfs/ddt.c b/module/zfs/ddt.c index d854e5f23..0ce8ca1a9 100644 --- a/module/zfs/ddt.c +++ b/module/zfs/ddt.c @@ -43,7 +43,7 @@ static kmem_cache_t *ddt_entry_cache; /* * Enable/disable prefetching of dedup-ed blocks which are going to be freed. */ -int zfs_dedup_prefetch = 1; +int zfs_dedup_prefetch = 0; static const ddt_ops_t *ddt_ops[DDT_TYPES] = { &ddt_zap_ops,