NAS5540 with RAID 5 recomputing parity from time to time

Reinhold

Last Sunday my NAS540 again started do recompute RAID 5 parity. As I had to switch it of, I lost connection and it took some time until reconnect was possible again.

Why does the system have to resync RAID 5 parity?

Thanks!

Reinhold

#NAS_Sep

Mijzelf

I think one of your disks is dropped from the array from time to time. I didn't know it would re-add that disk without command.

Reinhold

Strange. Having a hot spare I'd expect the system to switch to the hot spare.
I am not sure, but it may be that the problem occurs when I unplug the power supply for more that two days. I could test it, but I don't like the trouble when my assumption ist true.
I'll wait to see whether it happens again.