Bug 174753

Summary:	greater than one snapshots do not sync and behave the same as the first snapshot
Product:	Red Hat Enterprise Linux 4	Reporter:	Corey Marthaler <cmarthal>
Component:	lvm2	Assignee:	Jonathan Earl Brassow <jbrassow>
Status:	CLOSED NEXTRELEASE	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	4.3	CC:	agk
Target Milestone:	---
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Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	Bug Fix
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Last Closed:	2006-01-23 17:00:13 UTC	Type:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Embargoed:

Description Corey Marthaler 2005-12-01 22:07:13 UTC

Description of problem:
When I write files A B C to an origin fs, and then snap, those files show up in
the snap fs everytime without a sleep or a sync in between, however when I
create more files D E F to the origin, and then create a 2nd snap, those files
won't show up unless I do a sync before the 2nd snap or a sleep of >6 sec. In
ext2, even with the sleep of >6, the 2nd snap wont work without a manual sync
since it apparently doesn't have the same freeze hooks as ext3.

How reproducible:
everytime

Comment 1 Alasdair Kergon 2005-12-09 17:48:33 UTC

Need to think about this: have seen similar problem for a long time when using
loopback.  Is some flushing missing from lvm2 or dm?

Comment 2 Jonathan Earl Brassow 2005-12-14 00:16:03 UTC

haven't been able to reproduce this with kernel-2.6.9-24.EL

I was able to easily create it with earlier kernels

Comment 3 Jonathan Earl Brassow 2005-12-14 00:30:32 UTC

can't reproduce with kernel-2.6.9-25.EL either...  please verify

Comment 4 Corey Marthaler 2006-01-18 22:53:42 UTC

This appears to be fixed with the latest kern/rpms

[root@link-08 bin]# uname -ar
Linux link-08 2.6.9-28.ELsmp #1 SMP Fri Jan 13 17:08:22 EST 2006 x86_64 x86_64
x86_64 GNU/Linux
[root@link-08 bin]# rpm -q lvm2
lvm2-2.02.01-1.3.RHEL4
[root@link-08 bin]# rpm -q device-mapper
device-mapper-1.02.02-3.0.RHEL4

Comment 5 Alasdair Kergon 2006-01-19 17:47:04 UTC

OK - not sure of the precise cause, but I'll close this.