Bug 1140862

Summary:	A new xattr is needed to store ec parameters
Product:	[Community] GlusterFS	Reporter:	Xavi Hernandez <jahernan>
Component:	disperse	Assignee:	Xavi Hernandez <jahernan>
Status:	CLOSED CURRENTRELEASE	QA Contact:
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	3.6.0	CC:	bugs, gluster-bugs, ndevos
Target Milestone:	---	Keywords:	Triaged
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	glusterfs-3.6.0beta2	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	1140861	Environment:
Last Closed:	2014-11-11 08:38:42 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1140861
Bug Blocks:	1117822

Description Xavi Hernandez 2014-09-11 21:23:28 UTC

+++ This bug was initially created as a clone of Bug #1140861 +++

Description of problem:

Current ec implementation uses a special matrix with a fixed stripe size. This works fine, but most probably this will need to be changed or tweaked in the future to add features or performance. Since any change to this data involves changes in the encoding/decoding, it's necessary to store this information in each file to be able to recover it using the right configuration.

To do so, it's necessary to create a new xattr that will store this information and will allow backward compatibility.

Version-Release number of selected component (if applicable): master


How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info:

Comment 1 Anand Avati 2014-09-23 16:58:14 UTC

REVIEW: http://review.gluster.org/8825 (ec: Add config information in an xattr) posted (#1) for review on release-3.6 by Xavier Hernandez (xhernandez)

Comment 2 Anand Avati 2014-09-24 05:47:02 UTC

COMMIT: http://review.gluster.org/8825 committed in release-3.6 by Vijay Bellur (vbellur) 
------
commit c4440ab8c7417a3bcaadf1cb150476d5ff6a1325
Author: Xavier Hernandez <xhernandez>
Date:   Thu Sep 18 16:50:47 2014 +0200

    ec: Add config information in an xattr
    
    To simplify backward compatibility of the ec xlator when some
    parameter or the implementation itself is changed, a new xattr
    is added to each file with the configuration needed to recover
    it.
    
    The new attribute is called 'trusted.ec.config', and it's a 64-bit
    value containing the following information:
    
        8 bits: version of the config information (currently always 0)
        8 bits: algorithm used to encode the file (currently always 0)
        8 bits: size of the galois field (currently always 8)
        8 bits: number of bricks
        8 bits: redundancy
       24 bits: chunk size (currently 512)
    
    This new xattr could allow, in a future version, to have different
    configurations per file.
    
    This is a backport of http://review.gluster.org/8770/
    
    Change-Id: I8c12d40ff546cc201fc66caa367484be3d48aeb4
    BUG: 1140862
    Signed-off-by: Xavier Hernandez <xhernandez>
    Reviewed-on: http://review.gluster.org/8825
    Reviewed-by: Dan Lambright <dlambrig>
    Tested-by: Gluster Build System <jenkins.com>
    Reviewed-by: Vijay Bellur <vbellur>

Comment 3 Niels de Vos 2014-09-25 08:27:37 UTC

A beta release for GlusterFS 3.6.0 has been released. Please verify if the release solves this bug report for you. In case the glusterfs-3.6.0beta2 release does not have a resolution for this issue, leave a comment in this bug and move the status to ASSIGNED. If this release fixes the problem for you, leave a note and change the status to VERIFIED.

Packages for several distributions should become available in the near future. Keep an eye on the Gluster Users mailinglist [2] and the update (possibly an "updates-testing" repository) infrastructure for your distribution.

[1] http://supercolony.gluster.org/pipermail/gluster-users/2014-September/018883.html
[2] http://supercolony.gluster.org/pipermail/gluster-users/

Comment 4 Niels de Vos 2014-11-11 08:38:42 UTC

This bug is getting closed because a release has been made available that should address the reported issue. In case the problem is still not fixed with glusterfs-3.6.1, please reopen this bug report.

glusterfs-3.6.1 has been announced [1], packages for several distributions should become available in the near future. Keep an eye on the Gluster Users mailinglist [2] and the update infrastructure for your distribution.

[1] http://supercolony.gluster.org/pipermail/gluster-users/2014-November/019410.html
[2] http://supercolony.gluster.org/mailman/listinfo/gluster-users