Pool allocation classes

[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 41be2d8ba54c231023f442fd82b03fdf15e38656..25e4a41d18449d945b80c4eb349e85f31937bc3f 100644 (file)
--- a/man/man5/zfs-module-parameters.5
+++ b/man/man5/zfs-module-parameters.5
@@ -41,6 +41,21 @@ kstat.
 Default value: \fB0\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBdbuf_metadata_cache_max_bytes\fR (ulong)
+.ad
+.RS 12n
+Maximum size in bytes of the metadata dbuf cache.  When \fB0\fR this value will
+default to \fB1/2^dbuf_cache_shift\fR (1/16) of the target ARC size, otherwise
+the provided value in bytes will be used.  The behavior of the metadata dbuf
+cache and its associated settings can be observed via the
+\fB/proc/spl/kstat/zfs/dbufstats\fR kstat.
+.sp
+Default value: \fB0\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -77,6 +92,18 @@ of the target arc size.
 Default value: \fB5\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBdbuf_metadata_cache_shift\fR (int)
+.ad
+.RS 12n
+Set the size of the dbuf metadata cache, \fBdbuf_metadata_cache_max_bytes\fR,
+to a log2 fraction of the target arc size.
+.sp
+Default value: \fB6\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -296,7 +323,7 @@ Use \fB1\fR for yes (default) and \fB0\fR for no.
 \fBvdev_max_ms_count\fR (int)
 .ad
 .RS 12n
-When a vdev is added, it will be divided into approximately (but no more than) this number of metaslabs.
+When a vdev is added target this number of metaslabs per top-level vdev.
 .sp
 Default value: \fB200\fR.
 .RE
@@ -312,6 +339,17 @@ Minimum number of metaslabs to create in a top-level vdev.
 Default value: \fB16\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBvdev_ms_count_limit\fR (int)
+.ad
+.RS 12n
+Practical upper limit of total metaslabs per top-level vdev.
+.sp
+Default value: \fB131,072\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -1681,6 +1719,29 @@ otherwise would under the old \fBzfs_mg_alloc_failures\fR facility.
 Default value: \fB0\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_ddt_data_is_special\fR (int)
+.ad
+.RS 12n
+If enabled, ZFS will place DDT data into the special allocation class.
+.sp
+Default value: \fB1\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_user_indirect_is_special\fR (int)
+.ad
+.RS 12n
+If enabled, ZFS will place user data (both file and zvol) indirect blocks
+into the special allocation class.
+.sp
+Default value: \fB1\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -2473,6 +2534,19 @@ to limit potential SLOG device abuse by single active ZIL writer.
 Default value: \fB786,432\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzio_decompress_fail_fraction\fR (int)
+.ad
+.RS 12n
+If non-zero, this value represents the denominator of the probability that zfs
+should induce a decompression failure. For instance, for a 5% decompression
+failure rate, this value should be set to 20.
+.sp
+Default value: \fB0\fR.
+.RE
+
 .sp
 .ne 2
 .na