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Feature #1092

zfs refratio property

Added by Matthew Ahrens over 8 years ago. Updated over 8 years ago.

Status:
Resolved
Priority:
Normal
Category:
zfs - Zettabyte File System
Start date:
2011-06-06
Due date:
% Done:

90%

Estimated time:
Difficulty:
Medium
Tags:
needs-triage

Description

Add a "REFRATIO" property, which is the compression ratio based on data
referenced. For snapshots, this is the same as COMPRESSRATIO, but for
filesystems/volumes, the COMPRESSRATIO is based on the data "USED" (ie,
includes blocks in children, but not blocks shared with the origin).

This is needed to figure out how much space a filesystem would use if it were not compressed (ignoring snapshots).

Update manpage to clarify COMPRESSRATIO and REFRATIO properties:

compressratio
For  non‐snapshots,  the  compression ratio achieved for
the used space of this dataset, expressed as a multi‐
plier. The used property includes descendant datasets,
and, for clones, does not include the space shared with
the origin snapshot. For snapshots, the compressratio
is the same as the refratio property. Compression can
be turned on by running: zfs set compression=on dataset.
The default value is off.
refratio
The compression ratio achieved for the referenced space
of this dataset, expressed as a multiplier. See also
the compressratio property.

History

#1

Updated by Eric Schrock over 8 years ago

Based on review, the long name of the property has been updated to be "refcompressratio" and the short name will remain "refratio". This more closely matches the current "compressratio" semantics.

#2

Updated by Eric Schrock over 8 years ago

  • Status changed from New to Resolved

changeset: 13387:7dd5626b8b49
tag: tip
user: Matt Ahrens <Matt.Ahrens at delphix.com>
date: Mon Jun 13 18:04:20 2011 -0700

description:
1092 zfs refratio property
Reviewed by: George Wilson <George.Wilson at delphix.com>
Reviewed by: Adam Leventhal <Adam.Leventhal at delphix.com>
Reviewed by: Dan McDonald <danmcd at nexenta.com>
Reviewed by: Richard Elling <richard.elling at richardelling.com>
Reviewed by: Mark Musante <Mark.Musante at oracle.com>
Reviewed by: Garrett D'Amore <garrett at nexenta.com>
Approved by: Garrett D'Amore <garrett at nexenta.com>

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