[linux-lvm] snapshots and filesystem freezing
Tomasz Chmielewski
mangoo at wpkg.org
Fri Feb 8 12:04:46 UTC 2008
Some filesystems, like xfs, have a "freeze" feature. There was a
discussion on lkml about implementing it in ext3, too.
What is the relationship between a filesystem freeze and LVM snapshots?
As far as I understand, snapshotting a filesystem in any random
timepoint can mean that the snapshotted fs will be inconsistent (i.e.,
may need fsck).
"Freezing" the filesystem will flush all writes to the media, and a
snapshotted fs should be consistent then (in theory; without an
interface between filesystem freeze and LVM snapshot it does not
guarantee that the operation is "atomic").
Am I correct?
--
Tomasz Chmielewski
http://blog.wpkg.org
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