Bug 786626

Summary:	snapshots are reported as no longer being monitored every time a new snapshot is created
Product:	Red Hat Enterprise Linux 6	Reporter:	Corey Marthaler <cmarthal>
Component:	lvm2	Assignee:	LVM and device-mapper development team <lvm-team>
Status:	CLOSED NOTABUG	QA Contact:	Cluster QE <mspqa-list>
Severity:	low	Docs Contact:
Priority:	low
Version:	6.3	CC:	agk, dwysocha, heinzm, jbrassow, mbroz, prajnoha, prockai, thornber, zkabelac
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-02-15 17:36:11 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Corey Marthaler 2012-02-01 23:31:53 UTC

Description of problem:
Everytime a new snapshot is created, it is reported that any existing snapshot is no longer being monitored. This seems to be odd.

This issue is also mentioned in the following comment:
https://bugzilla.redhat.com/show_bug.cgi?id=707056#c1

qarshd[30865]: Running cmdline: lvcreate -s /dev/snapper/origin -c 32 -n 500_1 -L 50M
lvm[1202]: Monitoring snapshot snapper-500_1

qarshd[30902]: Running cmdline: lvcreate -s /dev/snapper/origin -c 32 -n 500_2 -L 50M
lvm[1202]: No longer monitoring snapshot snapper-500_1
lvm[1202]: Monitoring snapshot snapper-500_1
lvm[1202]: Monitoring snapshot snapper-500_2

qarshd[30941]: Running cmdline: lvcreate -s /dev/snapper/origin -c 32 -n 500_3 -L 50M
lvm[1202]: No longer monitoring snapshot snapper-500_1
lvm[1202]: No longer monitoring snapshot snapper-500_2
lvm[1202]: Monitoring snapshot snapper-500_1
lvm[1202]: Monitoring snapshot snapper-500_2
lvm[1202]: Monitoring snapshot snapper-500_3

qarshd[30988]: Running cmdline: lvcreate -s /dev/snapper/origin -c 32 -n 500_4 -L 50M
lvm[1202]: No longer monitoring snapshot snapper-500_1
lvm[1202]: No longer monitoring snapshot snapper-500_2
lvm[1202]: No longer monitoring snapshot snapper-500_3
lvm[1202]: Monitoring snapshot snapper-500_1
lvm[1202]: Monitoring snapshot snapper-500_2
lvm[1202]: Monitoring snapshot snapper-500_3
lvm[1202]: Monitoring snapshot snapper-500_4

qarshd[31043]: Running cmdline: lvcreate -s /dev/snapper/origin -c 32 -n 500_5 -L 50M
lvm[1202]: No longer monitoring snapshot snapper-500_1
lvm[1202]: No longer monitoring snapshot snapper-500_2
lvm[1202]: No longer monitoring snapshot snapper-500_3
lvm[1202]: No longer monitoring snapshot snapper-500_4
lvm[1202]: Monitoring snapshot snapper-500_1
lvm[1202]: Monitoring snapshot snapper-500_2
lvm[1202]: Monitoring snapshot snapper-500_3
lvm[1202]: Monitoring snapshot snapper-500_4
lvm[1202]: Monitoring snapshot snapper-500_5



Version-Release number of selected component (if applicable):
2.6.32-220.el6.x86_64
lvm2-2.02.90-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
lvm2-libs-2.02.90-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
lvm2-cluster-2.02.90-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
udev-147-2.40.el6    BUILT: Fri Sep 23 07:51:13 CDT 2011
device-mapper-1.02.69-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
device-mapper-libs-1.02.69-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
device-mapper-event-1.02.69-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
device-mapper-event-libs-1.02.69-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012
cmirror-2.02.90-0.25.el6    BUILT: Sat Jan 28 18:03:08 CST 2012


How reproducible:
Everytime

Comment 1 Alasdair Kergon 2012-02-02 00:15:43 UTC

I think it's harmless.  We should probably check what the code's doing is sensible and whether it's always done this or whether some recent change caused it.

Comment 2 Zdenek Kabelac 2012-02-05 16:08:14 UTC

I guess it's related to the way we process snapshot operations - before suspending snapshot - we 'unmonitor' all snapshots and after resume they are monitored again with new added snapshot as well.

We most probably may not optimize the amount of those operations for old-style snapshots.

Comment 3 Peter Rajnoha 2012-02-15 17:36:11 UTC

Well, I think these messages are OK and harmless - we have it logged what actually happens  and like Zdenek mentioned in comment #2 already, let's keep this working and let's not change this for old-style snapshots (if it could be corrected at all). These messages are there for a long time anyway...