MFC r286547:

5661 ZFS: "compression = on" should use lz4 if feature is enabled

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed by: Xin LI <delphij@freebsd.org>
Approved by: Robert Mustacchi <rm@joyent.com>
Author: Justin T. Gibbs <justing@spectralogic.com>

illumos/illumos-gate@db1741f555ec79def5e9846e6bfd132248514ffe

1 files changed, 17 insertions, 1 deletions

diff --git a/cddl/contrib/opensolaris/cmd/zfs/zfs.8 b/cddl/contrib/opensolaris/cmd/zfs/zfs.8
index f7335f5..a937a2c 100644
--- a/cddl/contrib/opensolaris/cmd/zfs/zfs.8
+++ b/cddl/contrib/opensolaris/cmd/zfs/zfs.8
@@ -939,7 +939,23 @@ Disabling checksums is
 .Em NOT
 a recommended practice.
 .It Sy compression Ns = Ns Cm on | off | lzjb | gzip | gzip- Ns Ar N | Cm zle | Cm lz4
-Controls the compression algorithm used for this dataset. The
+Controls the compression algorithm used for this dataset.
+Setting compression to
+.Cm on
+indicates that the current default compression algorithm should be used.
+The default balances compression and decompression speed, with compression
+ratio and is expected to work well on a wide variety of workloads.
+Unlike all other settings for this property, on does not select a fixed
+compression type.
+As new compression algorithms are added to ZFS and enabled on a pool, the
+default compression algorithm may change.
+The current default compression algorthm is either
+.Cm lzjb
+or, if the
+.Sy lz4_compress
+feature is enabled,
+.Cm lz4 .
+The
 .Cm lzjb
 compression algorithm is optimized for performance while providing decent data
 compression. Setting compression to