Add tunables for channel programs

[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 e3c6dd91a59e9ea42eb0c260aa65c8843cb63512..7a195ab1263344ee9ca7257e48e4643c33e485f1 100644 (file)
--- a/man/man5/zfs-module-parameters.5
+++ b/man/man5/zfs-module-parameters.5
@@ -1,6 +1,7 @@
 '\" te
 .\" Copyright (c) 2013 by Turbo Fredriksson <turbo@bayour.com>. All rights reserved.
 .\" Copyright (c) 2017 Datto Inc.
+.\" Copyright (c) 2018 by Delphix. All rights reserved.
 .\" The contents of this file are subject to the terms of the Common Development
 .\" and Distribution License (the "License").  You may not use this file except
 .\" in compliance with the License. You can obtain a copy of the license at
@@ -220,6 +221,18 @@ relative to the pool.
 Use \fB1\fR for yes (default) and \fB0\fR for no.
 .RE
 
+.sp
+.ne 2
+.na
+\fBmetaslab_force_ganging\fR (ulong)
+.ad
+.RS 12n
+Make some blocks above a certain size be gang blocks.  This option is used
+by the test suite to facilitate testing.
+.sp
+Default value: \fB16,777,217\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -339,6 +352,18 @@ they operate close to quota or capacity limits.
 Default value: \fB24\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBspa_load_print_vdev_tree\fR (int)
+.ad
+.RS 12n
+Whether to print the vdev tree in the debugging message buffer during pool import.
+Use 0 to disable and 1 to enable.
+.sp
+Default value: \fB0\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -401,6 +426,24 @@ create) will return ENOSPC.
 Default value: \fB5\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBvdev_removal_max_span\fR (int)
+.ad
+.RS 12n
+During top-level vdev removal, chunks of data are copied from the vdev
+which may include free space in order to trade bandwidth for IOPS.
+This parameter determines the maximum span of free space (in bytes)
+which will be included as "unnecessary" data in a chunk of copied data.
+
+The default value here was chosen to align with
+\fBzfs_vdev_read_gap_limit\fR, which is a similar concept when doing
+regular reads (but there's no reason it has to be the same).
+.sp
+Default value: \fB32,768\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -689,6 +732,18 @@ the code that may use them. A value of \fB0\fR will default to 6000 ms.
 Default value: \fB0\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_max_missing_tvds\fR (int)
+.ad
+.RS 12n
+Number of missing top-level vdevs which will be allowed during
+pool import (only in read-only mode).
+.sp
+Default value: \fB0\fR
+.RE
+
 .sp
 .ne 2
 .na
@@ -832,6 +887,47 @@ transaction record (itx).
 Default value: \fB5\fR%.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_condense_indirect_vdevs_enable\fR (int)
+.ad
+.RS 12n
+Enable condensing indirect vdev mappings.  When set to a non-zero value,
+attempt to condense indirect vdev mappings if the mapping uses more than
+\fBzfs_condense_min_mapping_bytes\fR bytes of memory and if the obsolete
+space map object uses more than \fBzfs_condense_max_obsolete_bytes\fR
+bytes on-disk.  The condensing process is an attempt to save memory by
+removing obsolete mappings.
+.sp
+Default value: \fB1\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_condense_max_obsolete_bytes\fR (ulong)
+.ad
+.RS 12n
+Only attempt to condense indirect vdev mappings if the on-disk size
+of the obsolete space map object is greater than this number of bytes
+(see \fBfBzfs_condense_indirect_vdevs_enable\fR).
+.sp
+Default value: \fB1,073,741,824\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_condense_min_mapping_bytes\fR (ulong)
+.ad
+.RS 12n
+Minimum size vdev mapping to attempt to condense (see
+\fBzfs_condense_indirect_vdevs_enable\fR).
+.sp
+Default value: \fB131,072\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -1123,7 +1219,7 @@ Default value: \fB1\fR.
 .sp
 .ne 2
 .na
-\fBzfs_free_max_blocks\fR (ulong)
+\fBzfs_async_block_max_blocks\fR (ulong)
 .ad
 .RS 12n
 Maximum number of blocks freed in a single txg.
@@ -1131,6 +1227,17 @@ Maximum number of blocks freed in a single txg.
 Default value: \fB100,000\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_override_estimate_recordsize\fR (ulong)
+.ad
+.RS 12n
+Record size calculation override for zfs send estimates.
+.sp
+Default value: \fB0\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -1375,9 +1482,6 @@ _
 16     ZFS_DEBUG_MODIFY
        Check for illegally modified ARC buffers.
 _
-32     ZFS_DEBUG_SPA
-       Enable spa_dbgmsg entries in the debug log.
-_
 64     ZFS_DEBUG_ZIO_FREE
        Enable verification of block frees.
 _
@@ -1457,6 +1561,30 @@ dataset being written to had the property setting \fBlogbias=throughput\fR.
 Default value: \fB32,768\fR.
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_lua_max_instrlimit\fR (ulong)
+.ad
+.RS 12n
+The maximum execution time limit that can be set for a ZFS channel program,
+specified as a number of Lua instructions.
+.sp
+Default value: \fB100,000,000\fR.
+.RE
+
+.sp
+.ne 2
+.na
+\fBzfs_lua_max_memlimit\fR (ulong)
+.ad
+.RS 12n
+The maximum memory limit that can be set for a ZFS channel program, specified
+in bytes.
+.sp
+Default value: \fB104,857,600\fR.
+.RE
+
 .sp
 .ne 2
 .na
@@ -1739,6 +1867,23 @@ Include cache hits in read history
 Use \fB1\fR for yes and \fB0\fR for no (default).
 .RE
 
+.sp
+.ne 2
+.na
+\fBzfs_reconstruct_indirect_combinations_max\fR (int)
+.ad
+.RS 12na
+If an indirect split block contains more than this many possible unique
+combinations when being reconstructed, consider it too computationally
+expensive to check them all. Instead, try at most
+\fBzfs_reconstruct_indirect_combinations_max\fR randomly-selected
+combinations each time the block is accessed.  This allows all segment
+copies to participate fairly in the reconstruction when all combinations
+cannot be checked and prevents repeated use of one bad copy.
+.sp
+Default value: \fB100\fR.
+.RE
+
 .sp
 .ne 2
 .na