Illumos 5034 - ARC's buf_hash_table is too small

[mirror_zfs.git] / man / man5 / zfs-module-parameters.5

diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5
index d23e8022ab4a7374cc0e555fe6288e392fa54411..4671c396f3450d44ec2acdbe84b6ab21b25f02a9 100644 (file)
--- a/man/man5/zfs-module-parameters.5
+++ b/man/man5/zfs-module-parameters.5
@@ -274,6 +274,22 @@ Min time before an active prefetch stream can be reclaimed
 Default value: \fB2\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_arc_average_blocksize\fR (int)
+.ad
+.RS 12n
+The ARC's buffer hash table is sized based on the assumption of an average
+block size of \fBzfs_arc_average_blocksize\fR (default 8K).  This works out
+to roughly 1MB of hash table per 1GB of physical memory with 8-byte pointers.
+For configurations with a known larger average block size this value can be
+increased to reduce the memory footprint.
+
+.sp
+Default value: \fB8192\fR.
+.RE
+
 .sp
 .ne 2
 .na