[Lustre-discuss] Migrating MDT volume to a new location

[Andreas Dilger]

On 2011-02-02, at 10:15, Bob Ball wrote:
> Is there a recommended way to migrate an MDT (MGS is separate) volume 
> from one location to another on the same server?  This uses iSCSI volumes.

This is all discussed in the manual.

The easiest way, if the device sizes are the same, is to use "dd" to just copy the raw data to the new device.  While a lot more data is copied, there is no seeking and it can go a lot faster.

If the new device is larger, it is possible to resize the new filesystem, though this isn't something that is tested.  You will have the old device for backup, in case something goes wrong.

If you decide to use something like tar, be sure to use the "--sparse" option.  That said, it may take a long time due to the way that the size is stored on the MDS.

Cheers, Andreas
--
Andreas Dilger 
Principal Engineer
Whamcloud, Inc.