Bug 712145

Summary:	RFE: striped mirrored legs which fail should be replaced with new striped legs
Product:	Red Hat Enterprise Linux 6	Reporter:	Corey Marthaler <cmarthal>
Component:	lvm2	Assignee:	Jonathan Earl Brassow <jbrassow>
Status:	CLOSED WONTFIX	QA Contact:	Cluster QE <mspqa-list>
Severity:	medium	Docs Contact:
Priority:	low
Version:	6.4	CC:	agk, bgollahe, dwysocha, heinzm, jbrassow, msnitzer, prajnoha, prockai, thornber, zkabelac
Target Milestone:	rc	Keywords:	FutureFeature
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:
Clones:	712146 (view as bug list)		Environment:
Last Closed:	2013-10-11 02:58:13 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Bug Depends On:
Bug Blocks:	712146

Description Corey Marthaler 2011-06-09 15:13:47 UTC

Description of problem:
Currently when a striped mirror leg is failed, lvm replaces it with a non striped leg.

# BEFORE the stripe leg failure

[root@taft-03 ~]# lvs -a -o +devices
  LV                VG           Attr   LSize  Log         Copy%   Devices
  stripe            revolution_9 mwi-a-  1.00G stripe_mlog 100.00  stripe_mimage_0(0),stripe_mimage_1(0)
  [stripe_mimage_0] revolution_9 iwi-ao  1.00G                     /dev/sdc1(0),/dev/sde1(0)
  [stripe_mimage_1] revolution_9 iwi-ao  1.00G                     /dev/sdf1(0),/dev/sdg1(0)
  [stripe_mlog]     revolution_9 lwi-ao  4.00M                     /dev/sdh1(0)

# leg device /dev/sdc is failed

# AFTER the stripe leg replacement

[root@taft-03 ~]# lvs -a -o +devices
  /dev/sdc1: read failed after 0 of 2048 at 0: Input/output error
  LV                VG           Attr   LSize  Log         Copy%   Devices
  stripe            revolution_9 mwi-ao  1.00G stripe_mlog  12.11  stripe_mimage_0(0),stripe_mimage_1(0)
  [stripe_mimage_0] revolution_9 Iwi-ao  1.00G                     /dev/sdf1(0),/dev/sdg1(0)
  [stripe_mimage_1] revolution_9 Iwi-ao  1.00G                     /dev/sde1(128)
  [stripe_mlog]     revolution_9 lwi-ao  4.00M                     /dev/sdh1(1)

Version-Release number of selected component (if applicable):
2.6.18-265.el5

lvm2-2.02.84-4.el5    BUILT: Thu Jun  2 05:04:32 CDT 2011
lvm2-cluster-2.02.84-3.el5    BUILT: Wed Apr 27 03:42:43 CDT 2011
device-mapper-1.02.63-3.el5    BUILT: Thu May 19 08:09:22 CDT 2011
device-mapper-event-1.02.63-3.el5    BUILT: Thu May 19 08:09:22 CDT 2011
cmirror-1.1.39-10.el5    BUILT: Wed Sep  8 16:32:05 CDT 2010
kmod-cmirror-0.1.22-3.el5    BUILT: Tue Dec 22 13:39:47 CST 2009


How reproducible:
Everytime

Comment 2 Alasdair Kergon 2011-10-17 19:51:32 UTC

It goes onto the list of low-priority enhancements to consider.  I doubt it will happen for 5.8.

Currently, striping parameters are a property of the allocation *event*.
They are not LV parameters.

So to do this, we'd either need to change the allocation model or else the leg replacement code would need a way to be told or to decide whether to use striping.

Perhaps we can find a clever way to do it, but it needs some careful thought.  Leave as NEW for now.

Comment 6 RHEL Program Management 2012-07-10 06:38:34 UTC

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

Comment 7 RHEL Program Management 2012-07-10 23:56:32 UTC

This request was erroneously removed from consideration in Red Hat Enterprise Linux 6.4, which is currently under development.  This request will be evaluated for inclusion in Red Hat Enterprise Linux 6.4.

Comment 8 Jonathan Earl Brassow 2012-11-19 15:31:16 UTC

Moving to rhel6.5.  This bug may eventually be closed WONTFIX.  We now have RAID10 and this old method of doing RAID-01 makes little sense.  That makes the priority of this bug extremely low.

Comment 9 Jonathan Earl Brassow 2013-10-11 02:58:13 UTC

I am closing this bug WONTFIX, for the reasons in comment 8.