My NAS has broken - swap disks to identical NAS

The advice that I would always give in this situation is that if you have valuable data that you do not want to lose, create images of the drives first. If you have spare drives available, you could do a block-based copy disk to disk and insert the copies into the other NAS. Whilst it is unlikely that a disk switchover would cause problems, having copies gives security.

As to whether or not it would work will depend on the old and secondary NAS devices being equivalent with the same firmware versions. If they are, you have a good chance of success. Many NAS devices, however, store boot configuration information on the drives, so swapping the drives may cause the alternative NAS to not boot. If the firmware versions are different, you may have joy, but do back up the drives before trying since some NAS systems may choose to initialise disks if they don't recognise them.

Many NAS devices use standard Linux partitions and Linux software RAID. With that in mind, taking images and connecting these to a PC that has booted a live Linux distro may offer some ability to recover data.

Notwithstanding what the post says, I would still take an image of the drives before doing anything if the data is of any value. 99% of the time everything works well but if that 1% happens, you are protected. Naturally, if the data is already backed up, you are good to go.

Yes indeed, always good to do that although I presume they also have a backup.

It may also behave differently if the replacement chassis/logic board is not brand new as it says something about importing.

@martyn: many NAS not only store config on the disk they also boot from them. where the first two disks have a mirrored pair with OS & system config. with all extra disks as spares for that partition.   (makes configuring & failover pretty easy).

Thanks @noci. I was aware of that (hence my mention of the boot configuration). It's going to depend on the NAS and I have heard horror stories of when people install drives into a NAS and it decides to re-initialise the array, wiping existing data. Since the OP does not make it clear about the backup situation, my comment was purely to help avoid data loss. I am not specifically familiar with the NAS models in question, but as a general rule, I would always image a drive before inserting it into a different NAS unit.

Thanks for the help guys. We did have a backup.

I moved the disks into the other working NAS and it prompted me to use the already used disks. The process took 5 minutes and all is working again perfectly.

Many thanks

Great to hear that it worked out well for you :) All the best.