2012-07-18 05:16 PM
Is it possible to change a drive from one raidgroup to another raidgroup? I have a FAS2020 with 12 disks in raidgroup 0 (rg0). I added a new DS14 shelf and 7 disks to the aggr. But the new disks ended up in another raidgroup (rg1). It was because the maximum raidsize was set to 12 per raidgroup.
Guess what, the problem is each raidgroup requires 2 parity disks (RAID-DP), so now I ended up with 4 parity disks for 18 disks (+ 1 spare)!! that's 4/18 = 22.22% of space GONE not to mention the WAFL already taken another 20% toll.
Now that I overrided the raidsize to 28, I want to move the 7 disk from rg1 to rg0 so I can save two disks from being parity disks.
Solved! SEE THE SOLUTION
2012-07-18 05:56 PM
You can't remove drives from an aggregate or raid group unles you are removing dual parity (that one drive only). The only way to combine the 2 is to destroy and recreate. Although I wouldn't go up to 28 per rg
2012-07-19 02:44 PM
Thanks for the confirmation, I was afraid that was the answer. I guess I just have to destory the lun and create. I do understand the risk that I am taking by overriding to 28 per rg. But this is not a mission-critical data storage. I am not planning to use all 28 disk per rg, I am using only 18, would that be okay?