Can additional disks be added to a RAID-5 Array?

[Kingy]

Hi all,

As title really, if you have a full RAID-5 array with 4 Hard Drives, can a 5th or 6th be added to give increased capacity without formatting the partition?

If not, how would you go about transferring the data (including boot partition) in the array to another array of larger disks? Would Ghost work for this?

Any help appreciated.

 

[rpstewart]

Most decent RAID5 cards will do Online Capacity Expansion to let you add disks to an existing array. It takes a while to do as all the data and parity has to be recalculated and redistributed about the new array but as the name suggests it can be done in the background.

What you don't get is an automatic expansion of the partitions on the array so it's back to the joys of Partition Magic if you need to do that. Alternatively create a new volume in the newly created space and mount it to a path in the original volume/partition.

 

[NickK]

Linux 2.6.11+ and EVMS supports the expansion/contraction of raid 5 & 6 volumes.

I've done it with mine and no data is lost during the expansion.

The time to complete the expansion goes up the larger the volume is. A 600GB raid 5 array expanded by 200GB took ten hours.