(original article)

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

31 October 2010, 05:39 UTC

I am stuck in my current situation with what would be the best procedure to follow.. I have an LVM on top of 2xRAID5 (6x 1TB each = 12 drives), and this gave me 9.5TB of usable space... which is now full. :(

I want to replace 1 RAID5 with 1.5TB drives, one at a time because I have no more HDD slots available. My idea was fail a drive, and then to create 2 partitions on the new drive (1TB + 500GB), making sure the 1TB was as large as existing drives. Allow for repair to finish, and repeat for remaining drives in array. Once done, add the remaining 6x 500GB to grow the array. I know this will be time-consuming but is this still do-able?

Otherwise, there's the option of failing a drive and adding the new 1.5TB drive to only use 1TB of it. Repeat until all 6 are swapped and repaired. But then how do I increase the array to use the 6x 500GB which is there but unseen? I was then thinking of replacing the other array with 2TB drives.

Copying all data off to another PC or collection of HDD would be difficult (home user) and a last resort. It also means that data from both arrays needs to be copied. If I did restart, would I be better off with 2x RAID6 array with 5 drives each (+1 each for raid6), or 1 RAID6 array with 11 drives (+1 for raid6)?