[linux-lvm] snapshots and reiserfs

[Mark M. Hoffman]

* Craig Ringer <craig at postnewspapers.com.au> [2004-04-10 16:28:32 +0800]:
> On Fri, 2004-04-09 at 02:18, Mark M. Hoffman wrote:
> 
> > kernel: reiserfs: checking transaction log (device 3a:06) ...
> > kernel: clm-2076: device is readonly, unable to replay log
> > kernel: Replay Failure, unable to mount
> > kernel: reiserfs_read_super: unable to initialize journal space
> 
> I upgraded my kernel to one provided by the Fedora project ( fedora.us,
> not fedora.redhat.com ). This seemed to sort out the problem.

What version?  I just looked at that site, and I don't see any kernel
RPMs except the stock RedHat ones (base and updates) for RedHat 9.

Or are you using FC1?  I'll upgrade, but only if I'm *sure* it will
solve the problem.

> > I have not tried the combination of snapshots & reiserfs with
> > earlier RedHat packages so I don't know if this is a regression.
> 
> I used to get it on RH8, with both ext3 and reiserfs (though more
> commonly with reiserfs). Syncing before taking the snapshot can help,
> but the only real fix is a kernel patch that makes sure the disk buffers
> are flushed to disk before the snapshot is taken.

Yeah, I already added a 'sync ; sleep 2' in front of the 'lvcreate' in
my scripts...  I'm still seeing some failures, but fewer than before.

> > Also, is it necessary that the filesystem be quiescent in order to
> > create a snapshot?  I could temporarily remount readonly to create
> > the snapshot, but I would like not to have to do that.
> 
> That would probably work too, but the VFS lock patch /really/ should do
> the trick.

That's what I understood as well; maybe RedHat's VFS lock patch is bad.

Thanks and regards,

-- 
Mark M. Hoffman
mhoffman at lightlink.com