I have a 2 disk NAS device using RAID 1 mirroring. When disks started failing I wanted to buy bigger disks so as to upgrade the volume size. However the device couldn't handle mirroring the original data from the smaller hard drive to the bigger drive. So my plan is to mount one of the old raid disks (keeping the other as an emergency backup) on an Ubuntu machine and just copy the data to the new, larger, RAID array in my NAS device.
How do I mount a single disk from the raid array on an Ubuntu machine to retrieve data from it?
--- different question, same answer ---
I have a 2 disk NAS device using RAID 1 mirroring. I have three disks. Periodically I swap a disk out of the NAS device to keep it in a safe place as a backup. The NAS device then automatically mirrors the existing data to the new disk.
If my house burns down, how would I mount the backup disk from the raid array on an Ubuntu machine to retrieve data from it?
--- More information ---
With the single hard disk mounted in my Ubuntu machine,
fdisk -l reports:
Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Disk identifier: D1C4E003-11FD-4223-AA98-61CB9C6322BD Device Start End Sectors Size Type /dev/sdb1 2048 1050623 1048576 512M Linux swap /dev/sdb2 3147776 3904929899 3901782124 1.8T Microsoft basic data /dev/sdb3 3904931840 3907029134 2097295 1G Microsoft basic data /dev/sdb4 1050624 3147775 2097152 1G Microsoft basic data
I tried steps from a similar question on this site:
root@host:/mnt# mount /dev/sdb2 /mnt/old_nas/ mount: /mnt/old_nas: unknown filesystem type 'linux_raid_member'. root@host:/mnt# mdadm --assemble --run /dev/md0 /dev/sdb2 mdadm: failed to RUN_ARRAY /dev/md0: Invalid argument mdadm: Not enough devices to start the array.
This must be quite a common thing to want to do so I am surprised not to already find a fully working answer.