Recovery after power supply failure

Normally in this situation you would have simply re-installed both of the original drives in their original slots with the NAS powered down, and then powered it up. You wouldn't hot-insert the drives, as that would wipe them.

One poster here accidentally got a V2 chassis from Netgear in exchange for a V1. You should probably make sure you got the same model, as the disk formats are different for different platform types.

Assuming the platform is the same-

If you don't want to put the old slot-1 drive in the NAS, you could try cloning it to the new drive on a PC first (using sector by sector copying, since the PC won't recognize the format).

Alternatively, you could take the plunge - powering down the NAS, inserting the original drive 1 in slot 1 (by itself, no other drives!). Then start up the NAS - and when it boots, then hot-add the new drive to slot 2.

If you follow the forum, you'll frequently see the "RAID is not a substitute for backup" mantra. It isn't, your data is always at risk if it is only stored on a single device. So I'd suggest putting a backup strategy in place. Perhaps you can install one of your 2 TB drives in a PC, and dedicate it to NV+ backup.

Thanks for the reply!

The hardware versions are both v3, though that was a great thing to recommend checking.

"powering down the NAS, inserting the original drive 1 in slot 1 (by itself, no other drives!). Then start up the NAS - and when it boots, then hot-add the new drive to slot 2." --- this is what I tried to do, per the second paragraph in my post; it does not boot with the data drive; it says "ERR: Bad firmwar". At no point did I hot-remove or hot-insert any drives. There was always a power-down between drive changes --- apologies if that was unclear.

Thank you for your good advice regarding backups, but my issue right now is that I have two drives which each independently have all my data. I have, if you will, two backups already in my hands. The issue is that the ReadyNAS will not read them. The "clumsy and time-consuming approach" I referred to above would be to buy a SATA adapter for my Linux laptop, mount one of the data-full drives, set up a network link to the NAS with a fresh drive, and transfer all the files. This seems like defeating the purpose of having a NAS system with swappable drives; since the instructions for getting new hardware per Netgear are "just plug it in" (http://www.readynas.com/kb/faq/boot/how_do_i_migrate_disks_over_from_an_existing_readynas_to_another), which is what I would have expected, I felt that I must be missing something.

So I suppose my question can be rephrased as: why, when I follow the instructions in the above how_do_i_migrate link, do I get a "firmware error"? I'm migrating one of the drives, not both; but a failed boot seems like a harsh error for a system that is designed to elegantly deal with having one of its drives disappear.

Thank you again for your thoughts on this, I truly appreciate your time and expertise.

Then you have a NV+ v1 hardware revision 3: How to tell whether I have a Duo v1 or Duo v2 or NV+ v1 or NV+ v2

Have you tried an OS Re-install?: http://www.readynas.com/kb/faq/boot/how_do_i_use_the_boot_menu

Again, the normal procedure would have been to remove the drive in slot 1, and replace it with the new drive while the NAS was running.

What you've done so far is insert a new drive into slot 1 with the NAS off - which I agree should have worked, but clearly it didn't.

Now that you've done all those reboots,etc, you are left with two drives in unknown states, and the original drive 1 in a known state. Let's call that one the "reference drive".

Trying the OS reinstall on the new drive (mdgm's suggestion) is reasonable, though of course if the NAS thinks the firmware is bad, the whole volume might well be corrupt. Definitely worth trying though, there is nothing to lose.

If that fails, I don't see much choice but to go back to the reference drive (presently "untouchable")

As I said, you can clone the reference drive with a program that does a physical sector-by-sector copy - giving you a "safe" copy to play with. Or you can risk the reference.

I'd start by putting the reference drive [or its clone] in the NAS by itself, as that really should boot up properly. Alternatively you can try pulling the data off with your PC, but you will need to get ext format support for windows as well as the SATA adapter. There are some freeware drivers you can try, there is also at least one commercial package that claims support for recovering data on linux drives onto Windows PCs.

Many thanks again for your time and thoughts. I was unclear as to what an OS Re-install would do, but at a minimum I assume it will lose all of my hard-won configurations (for SSH and various other services), sadly. But again thank you for the suggestion.

To be honest, the statement "which I agree should have worked" is the most reassuring one. It means that this really is a recovery situation --- the system did not work as we thought it should, and we don't know why, so we're on Plan B.

I apologize if I was unclear --- I do not use Windows, so the added complication involved there would be unnecessary. I'll order the SATA adapter for my Linux machine, and go from there. Thanks again for your expertise.

The "ERR: BAD FIRMWARE" appearing has multiple possible causes. Here are some examples:
1. Due to the power failure the OS on the disks got corrupted. An OS Re-install from the flash onto the disks should fix this
2. Problem with RAID and/or disks and OS partition won't mount
3. OS on flash is corrupt, possibly as well as the OS on the disks. USB Boot Recovery to load a good copy of the firmware onto the flash followed by OS Re-install to load that onto the disks would fix. I would not suggest trying a USB Boot Recovery as this is unlikely to be the problem in your case as you could get the system up doing a factory default.

1 is more likely than 2 and 3.

When you connect the disks up to your Linux PC I would suggest cloning the disks e.g. using dd_rescue before attempting data recovery. Also note if using X-RAID with two disks you could only use disk 1 for data recovery as disk 2 does not have the partition table on it.

After cloning the disks you could put the clone(s) of the disk(s) that still have your data in the NAS and try an OS Re-install. If it doesn't work you still have your original available for data recovery.