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author | delphij <delphij@FreeBSD.org> | 2014-07-01 06:43:15 +0000 |
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committer | delphij <delphij@FreeBSD.org> | 2014-07-01 06:43:15 +0000 |
commit | f95fd16f8d88667bcf37bb162d3f8fcc9f888cc7 (patch) | |
tree | 9f7200d4f5181a0103b0d7eb1ea7c229e3750211 /cddl/contrib/opensolaris/cmd/zpool/zpool-features.7 | |
parent | cd12aa0ab76d9d3638dc079c863eb0c93393a4d4 (diff) | |
parent | 3790348a90c72ae3b320ff6ce50ad718fd6ef61d (diff) | |
download | FreeBSD-src-f95fd16f8d88667bcf37bb162d3f8fcc9f888cc7.zip FreeBSD-src-f95fd16f8d88667bcf37bb162d3f8fcc9f888cc7.tar.gz |
MFV r267565:
4757 ZFS embedded-data block pointers ("zero block compression")
4913 zfs release should not be subject to space checks
MFC after: 2 weeks
Diffstat (limited to 'cddl/contrib/opensolaris/cmd/zpool/zpool-features.7')
-rw-r--r-- | cddl/contrib/opensolaris/cmd/zpool/zpool-features.7 | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/cddl/contrib/opensolaris/cmd/zpool/zpool-features.7 b/cddl/contrib/opensolaris/cmd/zpool/zpool-features.7 index 5560de9..d0f3ab2 100644 --- a/cddl/contrib/opensolaris/cmd/zpool/zpool-features.7 +++ b/cddl/contrib/opensolaris/cmd/zpool/zpool-features.7 @@ -23,7 +23,7 @@ .\" .\" $FreeBSD$ .\" -.Dd April 23, 2014 +.Dd June 30, 2014 .Dt ZPOOL-FEATURES 7 .Os .Sh NAME @@ -396,6 +396,34 @@ This feature becomes as soon as it is enabled and will never return to being .Sy enabled . +.It Sy embedded_data +.Bl -column "READ\-ONLY COMPATIBLE" "com.delphix:embedded_data" +.It GUID Ta com.delphix:embedded_data +.It READ\-ONLY COMPATIBLE Ta no +.It DEPENDENCIES Ta none +.El +.Pp +This feature improves the performance and compression ratio of +highly-compressible blocks. +Blocks whose contents can compress to 112 bytes +or smaller can take advantage of this feature. +.Pp +When this feature is enabled, the contents of highly-compressible blocks are +stored in the block "pointer" itself +.Po a misnomer in this case, as it contains +the compresseed data, rather than a pointer to its location on disk +.Pc . +Thus +the space of the block +.Pq one sector, typically 512 bytes or 4KB +is saved, +and no additional i/o is needed to read and write the data block. +.Pp +This feature becomes +.Sy active +as soon as it is enabled and will +never return to being +.Sy enabled . .El .Sh SEE ALSO .Xr zpool 8 |