[dm-devel] Recover filenames from failed RAID0

[keld at keldix.com]

Hi

Which file system did you use?
I once wrote some code to get files out of an ext3 filesystem, 
http://www.open-std.org/keld/readme-salvage.html

Maybe you can make some corrections for it to work
as I remember the code, then if you hit a directory, it will salvage the file names and the files
of that directory.

Best regards
keld

On Sun, Jul 17, 2016 at 03:10:03PM -0400, Michel Dubois wrote:
> Dear linux-raid mailing list,
> 
> I have a RAID0 array of four 3TB disks that failed on the "third" disk.
> 
> I am aware of the non-redundancy of RAID0 but I would like to recover
> the filenames from that RAID0. If I could recover some data it would
> be a bonus.
> 
> Below you'll find the outputs of the following commands
>  mdadm --examine /dev/sd[abcd]1
>  fdisk -l
> 
> where sda1, sdb1, sdc1 and sdd1 should be the 4 RAID devices.
> 
> What could be my next step?
> 
> I thank you for your time
> 
> Michel Dubois
> 
> ======================
> mdadm --examine /dev/sd[abcd]1
> /dev/sda1:
>           Magic : a92b4efc
>         Version : 00.90.00
>            UUID : 7d247a6e:7b5d46c8:f52d9c89:db304b21
>   Creation Time : Mon Apr 23 19:55:36 2012
>      Raid Level : raid1
>   Used Dev Size : 20980800 (20.01 GiB 21.48 GB)
>      Array Size : 20980800 (20.01 GiB 21.48 GB)
>    Raid Devices : 4
>   Total Devices : 3
> Preferred Minor : 0
> 
>     Update Time : Mon Jun 27 21:12:23 2016
>           State : clean
>  Active Devices : 3
> Working Devices : 3
>  Failed Devices : 1
>   Spare Devices : 0
>        Checksum : 1a57db60 - correct
>          Events : 164275
> 
> 
>       Number   Major   Minor   RaidDevice State
> this     0       8        1        0      active sync   /dev/sda1
> 
>    0     0       8        1        0      active sync   /dev/sda1
>    1     1       8       17        1      active sync   /dev/sdb1
>    2     2       0        0        2      faulty removed
>    3     3       8       33        3      active sync   /dev/sdc1
> /dev/sdb1:
>           Magic : a92b4efc
>         Version : 00.90.00
>            UUID : 7d247a6e:7b5d46c8:f52d9c89:db304b21
>   Creation Time : Mon Apr 23 19:55:36 2012
>      Raid Level : raid1
>   Used Dev Size : 20980800 (20.01 GiB 21.48 GB)
>      Array Size : 20980800 (20.01 GiB 21.48 GB)
>    Raid Devices : 4
>   Total Devices : 3
> Preferred Minor : 0
> 
>     Update Time : Mon Jun 27 21:12:23 2016
>           State : clean
>  Active Devices : 3
> Working Devices : 3
>  Failed Devices : 1
>   Spare Devices : 0
>        Checksum : 1a57db72 - correct
>          Events : 164275
> 
> 
>       Number   Major   Minor   RaidDevice State
> this     1       8       17        1      active sync   /dev/sdb1
> 
>    0     0       8        1        0      active sync   /dev/sda1
>    1     1       8       17        1      active sync   /dev/sdb1
>    2     2       0        0        2      faulty removed
>    3     3       8       33        3      active sync   /dev/sdc1
> /dev/sdc1:
>           Magic : a92b4efc
>         Version : 00.90.00
>            UUID : 7d247a6e:7b5d46c8:f52d9c89:db304b21
>   Creation Time : Mon Apr 23 19:55:36 2012
>      Raid Level : raid1
>   Used Dev Size : 20980800 (20.01 GiB 21.48 GB)
>      Array Size : 20980800 (20.01 GiB 21.48 GB)
>    Raid Devices : 4
>   Total Devices : 3
> Preferred Minor : 0
> 
>     Update Time : Mon Jun 27 21:12:23 2016
>           State : clean
>  Active Devices : 3
> Working Devices : 3
>  Failed Devices : 1
>   Spare Devices : 0
>        Checksum : 1a57db86 - correct
>          Events : 164275
> 
> 
>       Number   Major   Minor   RaidDevice State
> this     3       8       33        3      active sync   /dev/sdc1
> 
>    0     0       8        1        0      active sync   /dev/sda1
>    1     1       8       17        1      active sync   /dev/sdb1
>    2     2       0        0        2      faulty removed
>    3     3       8       33        3      active sync   /dev/sdc1
> 
> ======================
> fdisk -l
> 
> WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util
> fdisk doesn't support GPT. Use GNU Parted.
> 
> 
> Disk /dev/sda: 3000.5 GB, 3000592982016 bytes
> 255 heads, 63 sectors/track, 364801 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Disk identifier: 0x03afffbe
> 
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sda1               1      267350  2147483647+  ee  EFI GPT
> 
> WARNING: GPT (GUID Partition Table) detected on '/dev/sdb'! The util
> fdisk doesn't support GPT. Use GNU Parted.
> 
> 
> Disk /dev/sdb: 3000.5 GB, 3000592982016 bytes
> 255 heads, 63 sectors/track, 364801 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Disk identifier: 0x142a889c
> 
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdb1               1      267350  2147483647+  ee  EFI GPT
> 
> WARNING: GPT (GUID Partition Table) detected on '/dev/sdc'! The util
> fdisk doesn't support GPT. Use GNU Parted.
> 
> 
> Disk /dev/sdc: 3000.5 GB, 3000592982016 bytes
> 255 heads, 63 sectors/track, 364801 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Disk identifier: 0x3daebd50
> 
>    Device Boot      Start         End      Blocks   Id  System
> /dev/sdc1               1      267350  2147483647+  ee  EFI GPT
> 
> Disk /dev/md0: 21.4 GB, 21484339200 bytes
> 2 heads, 4 sectors/track, 5245200 cylinders
> Units = cylinders of 8 * 512 = 4096 bytes
> Disk identifier: 0x00000000
> 
> Disk /dev/md0 doesn't contain a valid partition table
> --
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