Unmountable Btrfs Cache Drives after Power Loss

[PhantamaroK]

Many months ago, I had a power outage in my home, and when my server boot back up, its SSD cache was unmountable. I found out that Btrfs is very sensitive to sudden power outages, and got a second NVMe drive to add to the cache pool for redundancy. Losing the appdata folder really hurt, and I had to remake most of my Docker containers from scratch.

 

Now, the same thing has happened again (power outage), and neither of the NVMe SSDs are mountable. I have scoured the forums, and all advice seemed to point here. I have followed all of those steps, and at each step, I see a message something to the effect of "no Btrfs filesystem found." Both drives were encrypted (via Cache Settings), which I assume interferes with the data recovery.

 

Can any kind soul give me some guidance? I'm trying to do a restore from a cloud backup, but it's months old, is taking forever, and may ultimately fail. I would be beyond grateful if I could recover that appdata folder from either of my 2 drives (which should each have the data). I have not at any point reformatted the drives.

[JorgeB]

4 hours ago, PhantamaroK said:

Both drives were encrypted (via Cache Settings), which I assume interferes with the data recovery.

Yes, it does, you need to adjust the paths, instead of:

 

/dev/nvmexxxp1

 

use

 

/dev/mapper/nvmexxxp1

 

[PhantamaroK]

13 hours ago, johnnie.black said:

Yes, it does, you need to adjust the paths, instead of:

 

/dev/nvmexxxp1

 

use

 

/dev/mapper/nvmexxxp1

 

Thank you for your help. When I try:

mount -t btrfs -o recovery,ro /dev/mapper/nvme1n1p1 /mnt/recovery/

I get:

wrong fs type, bad option, bad superblock on /dev/mapper/nvme1n1p1, missing codepage or helper program, or other error.

And when I try:

btrfs restore -v /dev/nvme1n1p1 /mnt/user/recovery/

I get:

No valid Btrfs found on /dev/nvme1n1p1
Could not open root, trying backup super
No valid Btrfs found on /dev/nvme1n1p1
Could not open root, trying backup super
No valid Btrfs found on /dev/nvme1n1p1
Could not open root, trying backup super

 

Do you have any ideas on how to proceed? I feel like I might still have a command wrong.

[PhantamaroK]

I caught an error I made. As noted, I should have used:

btrfs restore -vi /dev/mapper/nvme1n1p1 /mnt/user/recovery/

It now seems to be copying files!

Edited November 10, 2018 by PhantamaroK
Added flag for ignoring errors