On 11/11/19 10:44 AM, Paul Monsour wrote:
Hi,
I did it; I used dd and accidentally zapped all of my personal files, which were under the /home directory. This was a btrfs raid0 setup with /dev/sdc1 and /dev/sdd1. I aborted the command after it had started but before it had completed. Neither directory is now mountable, but btrfs fi show produced the following output:
[root@sysresccd /]# btrfs fi show
Label: none uuid: 9819165f-fade-471a-9f93-86f36523e58a
Total devices 1 FS bytes used 28.81GiB
devid 1 size 48.82GiB used 32.02GiB path /dev/sdb1
warning, device 2 is missing
Label: none uuid: 9985ee11-bc6d-4f06-ab15-3156457ba29c
Total devices 1 FS bytes used 32.75GiB
devid 1 size 58.59GiB used 45.06GiB path /dev/sdb5
Label: none uuid: 073f1926-d84d-4150-9498-4239b5383272
Total devices 2 FS bytes used 629.10GiB
devid 1 size 2.73TiB used 646.12GiB path /dev/sdc1
*** Some devices missing
parted -l produced:
Model: ATA ST3000DM008-2DM1 (scsi)
Disk /dev/sdc: 3001GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 3001GB 3001GB btrfs Home
Model: ATA ST3000DM008-2DM1 (scsi)
Disk /dev/sdd: 3001GB
Sector size (logical/physical): 512B/4096B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
2 119kB 1593kB 1475kB primary esp
The portion of the dd command that wrecked the files was "of=/dev/sdd1"
btrfs keeps 2 or 3 copies of superblock depending on the disk size,
you could try recover superblock from the backup superblock, but
first try to read all the superblocks using the command..
btrfs inspect-internal dump-super -a <dev>
And if there is any superblock copy which is still not overwritten.
you can recover using..
btrfs rescue super-recover [options] <device>
But depending on the extent of the accidental overwrite on the
RAID0, there is slim chances to recover the data and metadata.
HTH.
Thanks, Anand
btrfs restore produced just:
drwxr-xr-x 1 root root 0 Nov 10 12:43 ftp
drwxr-xr-x 1 root root 362 Nov 10 12:51 palsor
However, I was (perhaps optimistically) heartened by what "btrfs-find-root /dev/sdc1" produced:
# btrfs-find-root /dev/sdc1
warning, device 2 is missing
Superblock thinks the generation is 322292
Superblock thinks the level is 1
Found tree root at 649710272512 gen 322292 level 1
How do I use this information? Is there reason to be optimistic?
Thanks in advance for your help.
Paul Monsour
