I have a 2-bay pro 2, running with a 1 TB disk on OS6 in X-raid mode. I want to replace the 1TB disk with a 4TB disk, but without redoing the whole setup. I only have and need one drive. There is no need for redundancy and also the data is redundant available in another place on another readynas.
How can I achieve this? I already placed the 4TB disk in the unit, but now it is redundant at 1TB with the first 1TB disk. I could imagine there is a way with flex raid, but the description was not that easy, especially not on that use case...
If you need more tailored advice, please post your mdstat.log and also disk_info.log (both from the log zip).
Although it sounds like you already have a backup of your data, I do want to emphasize the importance of making a backup before attempting to run these commands (for the benefit of other readers).
It's not - this is fairly advanced stuff. You should make sure you have a backup of your NAS before you begin.
It's always a bit risky when I need to post linux commands that I can't actually test. Hopefully @Sandshark will chime in (as he's done experimenting with these commands and I have not).
In your system disk 1 (sda) is the 4 TB drive and disk 2 (sdb) is the 1 TB drive.
Start by changing to flexraid (web ui volume tab).
Remove disk 1 and reboot. At this point you should see your data volume (as before) and have access to your data. The array shouldn't be flagged as degraded.
Then try hot-inserting disk 1 again. You should be able to select it from the volume tab and create a new volume on it. If you have trouble (for instance if you see an "inactive volume"), then try connecting the disk to a PC (either SATA or USB adapter/dock) and zero it with Western Digital's Lifeguard utility. After that, hot-insert it again.
The zero-superblocks command listed by @StephenB is to insure your NAS doesn't try to re-integrate the drive into the current array when you return it to the chassis. For anyone not returning the drive to the NAS, it's not necessary.
The --force in the command above is necessary. The --verbose is not, but I always like visual confirmation of what's going on, which this provides.
The NAS will also need to re-sync the OS and swap partitions, but that's fast. You may see a message shortly after the reboot stating that sync is complete.
But then comes the part I'm not sure about. Will XRAID then start expansion of the volume to fill the 4TB drive, or can it be done in FlexRAID? My experiments were with equally sized drives, so I don't know. Even if it does, you'd end up with a very odd configuration: a 1TB single-drive RAID1 and a 3TB single-drive RAID1 on the same drive with a BTRFS file system spanning them. I could tell you how to do it manually, but then you'd definately be stuck needed to do all furure expansions manually.
Expanding the partition with GPARTED and then the RAID with MDADM would be a better way, but that's even more complex, in large part because GPARTED can't operate on a mounted partition.
Honestly, I'd recommend either a factory default with the 4TB and restore from backup or remove the 4TB from the array instead, and add it back as a new, separate volume. You'd still have the 1TB present, and as the primary OS device with your home folders, but you could move everything else to the 4TB.
Whether you could successfully EXPORT the 1TB after the 4TB is added as a new volume, I don't know, either.
You've given me food for thought should I ever try more experiments in this area.
But then comes the part I'm not sure about. Will XRAID then start expansion of the volume to fill the 4TB drive, or can it be done in FlexRAID?
I believe the goal here is to create a second volume on the 4 TB drive. That was why I suggested switching to flexraid before executing any of the ssh commands. Perhaps click on format before creating a new volume on the drive.
Thanks for all your input... Hmmmhh.... I will reevaluate the effort to do a fresh install of the NAS. In addition to the data there are some services and servers running that need then a new installation:
