(original article)

Re: Converting RAID5 to RAID6 and other shape changing in md/raid

05 January 2010, 20:25 UTC

Neil,

I was wondering if I could pick your brain and get opinions on my upgrade plan. I am currently running a 4x500GB RAID5 array that is about 80% full now. I've decided to upgrade to 5x2TB drives in a RAID6 configuration for extra redundancy. One thing that is a bit of a problem is that my machine can only support 5 drives, so I can't just attach the new drives and copy the data. I've come up with two options to do this upgrade:

1. Add one 2TB drive as a stand-alone, copy all data to the 2TB drive, replace the 4 old drives, create 4x2TB RAID6 array, copy data over from stand-alone drive, and finally expand the array to include the fifth drive.

2. Add 2TB drive, make current RAID5 array a RAID6 array including that drive, then swap out the 4 500GB drives one at a time as if they had each died.

I'm leading towards option 1 as I think that would be quicker, the longest part being the expanding of the array from 4 drives to 5 at the end, but the copying to and from the 2TB drive will probably just take several hours each way. It also seems fairly safe because I'll have the 4 500GB unaltered if anything should go wrong.

Thanks for any input, and thanks for all your hard work on this project.

Keith




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