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From: Tomasz Chmielewski <mangoo@wpkg.org>
To: LVM general discussion and development <linux-lvm@redhat.com>
Subject: [linux-lvm] snapshots and filesystem freezing
Date: Fri, 08 Feb 2008 13:04:46 +0100	[thread overview]
Message-ID: <47AC455E.4030502@wpkg.org> (raw)

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

             reply	other threads:[~2008-02-08 12:05 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-08 12:04 Tomasz Chmielewski [this message]
2008-02-08 12:28 ` [linux-lvm] snapshots and filesystem freezing Dan Kegel

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