NAS 540 Hot Spare

Franklin

Hi - the manual for NAS540 states this device on RAID1 supports Hot Spares
However the option is unavailable per screenshot attached.

Do I just insert a disk of >= the same capacity as the others and the option becomes available.

Does adding a 3rd disk to a x2 disk RAID 1 array cause any issues to the data if I experiment with above?

The manual states the NAS supports Hot Swapping disks. Is this feature available on NAS540?

I am using WD Red NASAware or WD RE Black

Many thanks for your help
Martin

hotswap.png

Mijzelf

I'm not sure why you (or anyone) would want a hotspare for raid1. For raid5 or -6 it makes sense. As soon as a member crashes the hotspare can be used to exchange it. It cannot be done before, because you don't know which member will crash first.

But in case of raid1 all members are identical. So if you reserve an extra disk for that array, just create a 3 disk raid1 array. In that case the disk is already contributing to the redundancy. The only drawbacks I see is a slightly higher power usage (a disk being written uses more juice than an idle one), and some wear. The advantages are that you won't have a silently dying hotspare, and that you are protected against 2 disk dying shortly after each other.

The manual states the NAS supports Hot Swapping disks. Is this feature available on NAS540?

Yes.

Mijzelf

I'm not sure why you (or anyone) would want a hotspare for raid1. For raid5 or -6 it makes sense. As soon as a member crashes the hotspare can be used to exchange it. It cannot be done before, because you don't know which member will crash first.

But in case of raid1 all members are identical. So if you reserve an extra disk for that array, just create a 3 disk raid1 array. In that case the disk is already contributing to the redundancy. The only drawbacks I see is a slightly higher power usage (a disk being written uses more juice than an idle one), and some wear. The advantages are that you won't have a silently dying hotspare, and that you are protected against 2 disk dying shortly after each other.

The manual states the NAS supports Hot Swapping disks. Is this feature available on NAS540?

Yes.

Franklin

Thank you very much for explaining this.

I guess I thought having this hot spare would speed up the re-syncing if a disc went down by simply swapping it. What you see makes total sense.

Appreciate your input to the forum, we'd be lost without you.