diff options
| author | Matthew Ahrens <[email protected]> | 2012-12-23 15:57:14 -0800 |
|---|---|---|
| committer | Brian Behlendorf <[email protected]> | 2013-01-08 10:35:43 -0800 |
| commit | 753c38392ddff9d3cf140bb4d28f3bfba52c92d2 (patch) | |
| tree | 628c9789ff88963dfdab65f37522640d13051dc8 /man/man5/zpool-features.5 | |
| parent | 91579709fccd3e55a21970742b66c388fb1403db (diff) | |
Illumos #3104: eliminate empty bpobjs
3104 eliminate empty bpobjs
Reviewed by: George Wilson <[email protected]>
Reviewed by: Adam Leventhal <[email protected]>
Reviewed by: Christopher Siden <[email protected]>
Reviewed by: Garrett D'Amore <[email protected]>
Approved by: Eric Schrock <[email protected]>
References:
illumos/illumos-gate@f17457368189aa911f774c38c1f21875a568bdca
illumos changeset: 13782:8f78aae28a63
https://www.illumos.org/issues/3104
Ported-by: Brian Behlendorf <[email protected]>
Diffstat (limited to 'man/man5/zpool-features.5')
| -rw-r--r-- | man/man5/zpool-features.5 | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/man/man5/zpool-features.5 b/man/man5/zpool-features.5 index 3c1930c35..0ab179ef7 100644 --- a/man/man5/zpool-features.5 +++ b/man/man5/zpool-features.5 @@ -169,5 +169,33 @@ through the \fBfreeing\fR property. This feature is only \fBactive\fR while \fBfreeing\fR is non\-zero. .RE + +.sp +.ne 2 +.na +\fB\fBempty_bpobj\fR\fR +.ad +.RS 4n +.TS +l l . +GUID com.delphix:empty_bpobj +READ\-ONLY COMPATIBLE yes +DEPENDENCIES none +.TE + +This feature increases the performance of creating and using a large +number of snapshots of a single filesystem or volume, and also reduces +the disk space required. + +When there are many snapshots, each snapshot uses many Block Pointer +Objects (bpobj's) to track blocks associated with that snapshot. +However, in common use cases, most of these bpobj's are empty. This +feature allows us to create each bpobj on-demand, thus eliminating the +empty bpobjs. + +This feature is \fBactive\fR while there are any filesystems, volumes, +or snapshots which were created after enabling this feature. +.RE + .SH "SEE ALSO" \fBzpool\fR(1M) |