I don't think (last time I tried) that there's a way to switch RAID level in-place so expanding that in future will require starting again and copying to and then back from other drives again. If you could create a RAID5 now but with a missing drive that would provide the same mirroring for now and allow it to be easily grown later with 3TB drives but it won't (wouldn't when I tried) create a RAID5 without min 3 drives.
It's possible to frig it using some mdadm trickery but I expect that's not recommended...
Neil
On 14/10/2013 13:29, Mark Rogers wrote:
On 14 October 2013 13:15, mick mbm@rlogin.net wrote:
And that gives me the answer to what I need to do later when I eventually replace the disks in my RAID1 setup. I have a spare box I can use.
On checking, I find that of the >5TB I have available in my existing array I'm only using <2TB of it anyway, just goes to show it's worth checking these things! So 2x3TB in RAID1 config gives me two spare drive bays to expand in future should I need to and is more cost effective. I've gone with Toshiba drives, whether or not that'll prove to be a good choice I have no idea (I don't use Seagate now that they only put 1yr warranty on them, so it was either Tosh or WD at the price point I was looking at).