[nine_k]

RAID6 should be fine rebuilding online (in RAID5 mode) even under a moderate write load.

Of course one should source RAID disks form 3 different vendors, to ensure that they are from different batches, and are not going to fail at approximately the same time.

[stephengillie]

Do other manufacturers produce this size of drive? It's difficult to source from 3 vendors if there's only one making the product.

[thfuran]

Get one from amazon, one from newegg, one from the manufacturer directly or some such.

[lostapathy]

I try to buy hot spare or the last drive in a raid6 later than the rest of the array to try to spread them out too.

[tracker1]

Good advice, though I once had about half a dozen drives (12 drive RAID Z2 with 2 as hot spares) fail within a few weeks of each other in separate batches from sourcing. (Seagate 3TB drives, I think there's been articles on how bad that series was).

[tfigment]

I don't know how i survived those Seagates. Lasted maybe a year and started dropping like flies. Synology seems to recommend identical drives as i recall but work fine with different sizes and makers afaict.