Hi Eric,
Thanks for the response. It sounds like I only have to worry about
snapshotting the data volume and then if my external log is on another
device I can just reset it using dd and the configured block-size and block
count, which the log was created with. Is this to prevent me from having an
inconsistent file-system? And it also sounds like the zeroing of the log is
only necessary if I implement a rollback. Otherwise the log and the
filesystem should be consistent. I hope that makes sense to you. I'm just
trying to see if I've got the gist of things.
-Mike
-----Original Message-----
From: Eric Sandeen [mailto:sandeen@xxxxxxx]
Sent: Monday, February 02, 2004 5:38 PM
To: Mike Young
Cc: freemyer-ml@xxxxxxxxxxxxxxxxx; linux-xfs@xxxxxxxxxxx
Subject: RE: Snapshots with external logs
freeze does indeed flush the log; in fact it also
writes an unmount record to disk. If you're snapshotting
off to some other device and want to mount it, just have
any old device around that is at least as big as your log,
and dd zeros into it to zero the whole log space. Then you
can mount it up. If I'm understanding what you're
asking...
-Eric
On Mon, 2 Feb 2004, Mike Young wrote:
> Hi Greg,
>
> Thanks for the quick response.
>
> I'm using LVM for the snapshot and rollback. You're right it is doing an
> xfs_freeze, which does flush the log to disk. So, without the log
present,
> I'm sure I'm going to have to use some option at mount time to create a
new
> log. Is this a correct assumption? Do you know what the option will be
so
> I can just automate the mount?
>
> Thanks,
>
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