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From: "Paul Monsour" <>
Subject: dd does it again!
Date: Mon, 11 Nov 2019 03:44:40 +0100
Message-ID: <trinity-9b5e3549-dd52-48e7-98f1-9f8bfd1a358a-1573440280042@3c-app-mailcom-bs04> (raw)


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 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

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Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-11  2:44 Paul Monsour [this message]
2019-11-11  5:19 ` Anand Jain
2019-11-11 19:19 ` Chris Murphy

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