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I've created a RAID0 configuration with two 1GB EBS volumes, mounted at /dev/md0 using mdadm and formatted with XFS Next, I copied some files over to fill the volume to around 30% of its capacity (of 2GB)

I then created snapshots of the volumes using ec2-consistent-snapshot and created volumes of the said snapshots but specified the volume size to be 2GB (effective doubling the capacity on each disk)

I then spun up a new instance, assembled the RAID0 configuration on /dev/md0 from the 2 volumes mentioned above and mount it to /vol

df -hT showed /vol as 2GB (as expected)

Now I ran sudo xfs_growfs -d /vol. The command completed normally but reported blocks changed from 523776 to 524160 (only!) and df -hT still showed /vol as 2GB (instead of the expected 4GB)

I rebooted, remounted, reassembled the RAID but it still reports the old size.

EDIT: trying to grow the RAID using mdadm --grow yields mdadm: raid0 array /dev/md0 cannot be reshaped

Is there any other way I can grow a RAID0 array?

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I can really strongly urge you not to do this, R0 is bad enough when you're using DAS, but using in a situation where the SLA is already wooly enough and where outages DO occur is I believe only asking for trouble. If you want so extra performance at least R10 them. – Chopper3 Feb 27 '11 at 12:10
I assume that EBS is a abstraction over a highly-redundant data store. If this is true then R10 would not add extra value. – Ryan Fernandes Feb 28 '11 at 6:54
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One solution is to create new set of volumes from scratch (2GB each) and assemble a new RAID0 configuration in parallel (say, /dev/md1). Copy the files from one raid volume (/dev/md0) to the other (/dev/md1).

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yup! thats what I thought. In the absence of any other replies, I'll accept yours and move on. Thanks! – Ryan Fernandes Feb 28 '11 at 6:55
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