My RAID 1 NAS (2 x 2TB) had a disk crash.
It was the boot drive (drive 1 according to the error on the display).
It appears, according to Buffalo tech support, that once I replace the drive and format it I'll have the option to rebuild the array. So, as long as drive 2 is not bad my backups will be restored.
As a protection, I bought two replacement drives.
Did I do good?