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Re: How to Clone a RAID1 Box to Another with Drives Twice As Big?

On Thu, Nov 09, 2017 at 12:25:17PM -0600, Kent West wrote:
>    I have a Debian Stable box with two 1TB drives, set up as a mirrored RAID1
>    setup.
>    I have a replacement box with two 2TB drives.
>    How do I best clone the old machine to the new, with minimal (or better,
>    no) downtime, being able to wind up with double the drive space on the new
>    box?

If minimizing downtime is your objective, then I would recommending
doing a fresh install on the replacement system and rsyncing everything
over.  That lets you have the old system up and running until the very
last moment.

Of course, if you want a true clone (i.e., block for block disk image),
then I would recommdend shutting down the old machine, plugging the old
drives into the new machine, booting a live image, and then transferring
everything from each old drive to its new counterpart with dd.

Once the dd operations are complete, then you can either create new
partitions to use the free space and then assemble the new pair of
partitions into a new /dev/md? device that you can use.  If you are also
using LVM, then you add the new /dev/md? as a physical volume to your
system's volume group.  That way you would be able to create new logical
volumes.  Alternatively, you could resize the last partition on each
disk to take advantage of the additional space.  However, the
suitability of that approach depends on your current partition scheme.



Roberto C. Sánchez