dual-ported raid

[Chris Worley]

You can do it if the two systems use different luns for their
ext/reiser/xfs file system, or if you use GFS as the file system
(then, you can mount the same FS read/write).

On 10/16/06, Andreas Dilger <adilger at clusterfs.com> wrote:
> On Oct 16, 2006  12:04 -0500, Jeff Garlough wrote:
> > What I would like to do is use one
> > normally, and mount the second system read-only to perform backups and
> > to rsync the filesystem to another filesystem. When it's mounted
> > read-write from another system, will mounting the same filesystem
> > read-only cause the journal to be committed at the time it's mounted?
>
> Yes, that is very bad.
>
> > If so, is that a bad thing, that is, will it corrupt the filesystem?
>
> Yes, it can corrupt the filesystem.
>
> > Are journal events handled similar to databases, with regard to transaction
> > processing of journal events, or could playing "partial" journal events
> > (if there is such a thing) cause corruption?  Is mounting the read-only
> > instance as a ext2 filesystem the best solution, or does it matter if
> > it's mounted ext2 or ext3 as long as it's read-only?
>
> You can't mount it as ext2.
>
> I would instead use a block-device level backup, like "dump" if you really
> need to do it this way.  You are probably better off just doing the backup
> from the primary node.
>
> Cheers, Andreas
> --
> Andreas Dilger
> Principal Software Engineer
> Cluster File Systems, Inc.
>
> _______________________________________________
> Ext3-users mailing list
> Ext3-users at redhat.com
> https://www.redhat.com/mailman/listinfo/ext3-users
>