[CentOS] Turn an ext2 filesystem into a component of a mirrored RAID?

Bart Schaefer barton.schaefer at gmail.com
Mon Nov 27 23:04:57 UTC 2006

On 11/27/06, Les Mikesell <lesmikesell at gmail.com> wrote:
> If you can be down a few hours, you should be able to boot the
> install CD in rescue mode and
> dd bs=1M if=/dev/hda of=/dev/hdb (being very careful that those
> are the correct devices for the source and target respectively).
> I'd expect that to take about 3 hours to complete, depending on
> your drives and controller.

That may be what we have to try.  This isn't the root filesystem, so
we should just be able to unmount it during the dd and not have to

> Another approach
> would be to put the drive directly in the 2nd server and do the
> rsync over the network.  This would probably complete over a weekend.

The second server is 2900 miles away in another data center with no
dedicated network between the locations, so this probably isn't going
to work ...

> If the files are changing, you can do one run with the machine active,
> then repeat it when no changes are happening.  The 2nd run should go
> very quickly since it only has to copy the differences.

Unfortunately we're talking about a relatively small number of
relatively huge files, so the checksumming is a significant portion of
the rsync time.

Thanks, everyone, for your responses so far.

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