N5200 raid6 problem

[mtcsltd]

Today I was editing some excel spreadsheets on the NAS. For some reason one of the spreadsheets became read only, then access to it slowed down. I decided to restart the NAS. When it came back up I got an email saying the raid is suffering disk problems and that raid is endangered. When I logged on to take a look, tray 1 and 3 were not showing as installed. I shut down the N5200, then removed and re-inserted those trays, then restarted, all drives were showing as OK, though the raid is degraded - I assume it's rebuilding.

The N5200 (Routster model) firmware level is V2.00.08 and the drives are Samsung spinpoint HD103UJ 1Tb models which are about 4 months old.

I don't think there is a problem with the drives, but I can't explain the hic-cup with the N5200. Is it likely to be resolved by updating the firmware?

Thanks
Mike

[mtcsltd]

Since my post yesterday the array has been in a degraded state. The 2 drives that were offline are showing as OK, but I can't tell if the array is re-building.
In the raid configuration, the status columns is OK for all drives, the used column are all greyed out with a tick except for tray 1 & 3 which is just greyed out. There is a 'spare' column which are all empty but for tray 1 & 3 they are tickable. Do I need to tick them and apply, then untick and apply to make the N5200 re-use the drives?
The last time I built the array, I did it one drive at a time and it showed my the build progress, but this time I can't tell if it's actually re-building or not. Whenever I added another 1Tb drive it took about 12-13 hours to bring it into the array, so maybe with 2 drives it's going to take 24 hours, in which case I've got a few more hours to wait :-)
The lack of information I can see on what the array is doing is a bit frustrating. Maybe I just need to be patient!

[peterfu]

If You tick the spare drive, then the raid rebuild starts and the spare drives are then part of the raid - no need for untick them afterwards
br
Peter

[mtcsltd]

Thank you Peter. That did the trick.

Going back to why 2 good drives stopped working, and then were OK, has anyone any thoughts/theories on how this can happen? I thought perhaps heat expansion could affect the drive bays but it wasn't an especially warm day when it happened, it doesn't seem very plausable.