Change number of disks in Raid 1 setup?

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coldmist
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Change number of disks in Raid 1 setup?

Post by coldmist » Thu Mar 20, 2008 12:22 pm

I just got a 409 and 3 WD 750GB drives. I plugged all 3 in, and set them up as a Raid 1.

Now, I'd like to pull 1 of the drives out, and just use 2 of the drives as Raid 1, but not have it report the raid as being in a degraded mode forever?

I also do not reformat and start over.

Is there an easy way to tell the 409 to accept the 2 disks as "normal" from now on?
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fribse
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Re: Change number of disks in Raid 1 setup?

Post by fribse » Thu Mar 20, 2008 4:35 pm

coldmist wrote:I just got a 409 and 3 WD 750GB drives. I plugged all 3 in, and set them up as a Raid 1.
Is there an easy way to tell the 409 to accept the 2 disks as "normal" from now on?


Three discs in Raid-1??? Sounds very odd, are you sure it's not Raid-5? Raid-1 is mirrored, I've never done this with an uneven number of discs, cause where would the last disc be mirrored to?

To the question, no, no RAID controller can as far as my experience go, reduce the amount of discs. You can expand, and change raid level, but only to provide more space, not less space. You'll have to empty the array, reconfig, and fill it back up.
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coldmist
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Re: Change number of disks in Raid 1 setup?

Post by coldmist » Thu Mar 20, 2008 5:16 pm

Ok, this is interesting. I set all 3 up to be raid 1 (just to try it) in bays 2,3,4. For fun, I pulled drive 2 out, and saw it rebuilding the array between drives 3,4. Then, I plugged drive 2 back in, and didn't think much of it.

So, I just looked at the admin screen, and it says that drives 2,3 are mirrored, but drive 4 is a single disk. (I do remember it saying rebuilding 2,3 when I plugged it back in.)

So, I pulled it. (I got an email saying it was 'plugged out'.) The logical volumes now show 2,3 are still mirrored.

So, now, I will try pulling drive 3, and it should go into degraded mode, and then I will plug 4 back in, and see what it does ;) (tomorrow)

It would be very cool if I can then say 'use disk 2,4 as a mirror set', and then pull 4, put 3 back in, and see if it will rebuild 2,3 as a mirror set, or 3,4 (either way).

I'm just having fun with it, but if I don't have to start over from scratch, all the better. I would rather tinker now and understand how it works, than to get caught unprepared down the road.
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Epstein
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Re: Change number of disks in Raid 1 setup?

Post by Epstein » Thu Mar 20, 2008 7:33 pm

Just to clear something up. You can use as many discs as you want in a Raid1, all discs will contain the same information because it's mirrored.
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coldmist
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Re: Change number of disks in Raid 1 setup?

Post by coldmist » Fri Mar 21, 2008 9:10 am

Ya, that's how I thought I set it up with the first 3 initial disks. But, once I pulled one disk and put it back in, it only had a Raid 1 between 2 disks and the third disk was now a separate volume.

I wonder if that is a bug on Qnap's part?
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