Bug 855123

Summary:	RFE: allow the creation of read-only thinp snapshots
Product:	Red Hat Enterprise Linux 6	Reporter:	Corey Marthaler <cmarthal>
Component:	lvm2	Assignee:	Zdenek Kabelac <zkabelac>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Cluster QE <mspqa-list>
Severity:	low	Docs Contact:
Priority:	low
Version:	6.3	CC:	agk, 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:		Environment:
Last Closed:	2013-06-03 11:57:52 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:

Description Corey Marthaler 2012-09-06 18:23:03 UTC

Description of problem:
SCENARIO - [create_ro_snap]
Making origin volume
Creating thinpool and corresponding thin origin volume
lvcreate --thinpool POOL -L 1G snapper_thinp
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n origin
Making read only snapshot
lvcreate -s /dev/snapper_thinp/origin -p r -n readonly
  Read-only thin volumes are not currently supported.




Version-Release number of selected component (if applicable):
2.6.32-279.el6.x86_64
lvm2-2.02.95-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
lvm2-libs-2.02.95-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
lvm2-cluster-2.02.95-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
udev-147-2.41.el6    BUILT: Thu Mar  1 13:01:08 CST 2012
device-mapper-1.02.74-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
device-mapper-libs-1.02.74-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
device-mapper-event-1.02.74-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
device-mapper-event-libs-1.02.74-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012
cmirror-2.02.95-10.el6    BUILT: Fri May 18 03:26:00 CDT 2012

Comment 1 Zdenek Kabelac 2012-09-07 14:04:40 UTC

Yep, we need to modify condition to make a difference between old-style snapshots and new thin snapshots.

Comment 2 Tom Lavigne 2012-09-07 15:27:02 UTC

This request was evaluated by Red Hat Product Management for 
inclusion in the current release of Red Hat Enterprise Linux.
Since we are unable to provide this feature at this time,  
it has been proposed for the next release of 
Red Hat Enterprise Linux.

Comment 3 Corey Marthaler 2013-05-31 20:20:33 UTC

Looks like this went into rhel6.4 after all.

SCENARIO - [create_ro_snap]
Making origin volume
lvcreate --thinpool POOL -L 1G snapper_thinp
Sanity checking pool device metadata
(thin_check /dev/mapper/snapper_thinp-POOL_tmeta)
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n origin
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n other1
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n other2
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n other3
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n other4
lvcreate --virtualsize 1G --thinpool snapper_thinp/POOL -n other5
Making read only snapshot
lvcreate -s /dev/snapper_thinp/origin -p r -n readonly
Attempting to write to ro snap
dd: writing to `/dev/snapper_thinp/readonly': Operation not permitted
1+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000418191 s, 0.0 kB/s

2.6.32-354.el6.x86_64

lvm2-2.02.98-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
lvm2-libs-2.02.98-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
lvm2-cluster-2.02.98-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
udev-147-2.46.el6    BUILT: Tue Jan 15 06:41:59 CST 2013
device-mapper-1.02.77-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
device-mapper-libs-1.02.77-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
device-mapper-event-1.02.77-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
device-mapper-event-libs-1.02.77-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013
cmirror-2.02.98-9.el6    BUILT: Wed Jan 23 10:06:55 CST 2013