Re: Two partitionless BTRFS drives no longer seen as containing BTRFS filesystem

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

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On 2018/10/7 上午7:23, evan d wrote:
> I have two hard drives that were never partitioned, but set up as two
> independent BRTFS filesystems.  Both drives were used in the same
> machine running Arch Linux and the drives contain(ed) largely static
> data.
> 
> I decommissioned the machine they were originally used in and on
> installing in a newer Arch build found that BRTFS reported no
> filesystem on either of the drives.

Please try "btrfs ins dump-super -fFa" on these two disks.

If it's only the primary superblock corrupted, the backup should be good.

If backup is also corrupted, either it has some offset or the whole data
is corrupted.

Thanks,
Qu

> 
> uname -a:
> Linux z87i-pro 4.18.9-arch1-1-ARCH #1 SMP PREEMPT Wed Sep 19 21:19:17
> UTC 2018 x86_64 GNU/Linux
> 
> btrfs --version: btrfs-progs v4.17.1
> btrfs fi show: returns no data
> 
> parted -l:
> Error: /dev/sdb: unrecognised disk label
> Model: ATA WDC WD60EFRX-68M (scsi)
> Disk /dev/sdb: 6001GB
> Sector size (logical/physical): 512B/4096B
> Partition Table: unknown
> Disk Flags:
> 
> gdisk /dev/sdb - l:
> Error: /dev/sdc: unrecognised disk label
> Model: ATA WDC WD60EFRX-68M (scsi)
> Disk /dev/sdc: 6001GB
> Sector size (logical/physical): 512B/4096B
> Partition Table: unknown
> Disk Flags:
> 
> gdisk /dev/sdb -l
> GPT fdisk (gdisk) version 1.0.4
> 
> Caution: invalid main GPT header, but valid backup; regenerating main header
> from backup!
> 
> Caution! After loading partitions, the CRC doesn't check out!
> Warning: Invalid CRC on main header data; loaded backup partition table.
> Warning! Main and backup partition tables differ! Use the 'c' and 'e' options
> on the recovery & transformation menu to examine the two tables.
> 
> Warning! One or more CRCs don't match. You should repair the disk!
> Main header: ERROR
> Backup header: OK
> Main partition table: ERROR
> Backup partition table: ERROR
> 
> Partition table scan:
>   MBR: protective
>   BSD: not present
>   APM: not present
>   GPT: damaged
> 
> ****************************************************************************
> Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
> verification and recovery are STRONGLY recommended.
> ****************************************************************************
> Warning! Main partition table overlaps the first partition by 33 blocks!
> You will need to delete this partition or resize it in another utility.
> Disk /dev/sdb: 11721045168 sectors, 5.5 TiB
> Model: WDC WD60EFRX-68M
> Sector size (logical/physical): 512/4096 bytes
> Disk identifier (GUID): FB26D91F-0709-11E7-B298-3464A99AF244
> Partition table holds up to 128 entries
> Main partition table begins at sector 2 and ends at sector 33
> First usable sector is 34, last usable sector is 11721045134
> Partitions will be aligned on 8-sector boundaries
> Total free space is 11721045101 sectors (5.5 TiB)
> 
> Number  Start (sector)    End (sector)  Size       Code  Name
>   69               1               6   3.0 KiB     FFFF  犀읭퇸䵧羒⌦盤䧔Ẑ坔
> 
> gdisk /dev/sdc -l:
> GPT fdisk (gdisk) version 1.0.4
> 
> Caution: invalid main GPT header, but valid backup; regenerating main header
> from backup!
> 
> Caution! After loading partitions, the CRC doesn't check out!
> Warning: Invalid CRC on main header data; loaded backup partition table.
> Warning! Main and backup partition tables differ! Use the 'c' and 'e' options
> on the recovery & transformation menu to examine the two tables.
> 
> Warning! One or more CRCs don't match. You should repair the disk!
> Main header: ERROR
> Backup header: OK
> Main partition table: ERROR
> Backup partition table: ERROR
> 
> Partition table scan:
>   MBR: protective
>   BSD: not present
>   APM: not present
>   GPT: damaged
> 
> ****************************************************************************
> Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk
> verification and recovery are STRONGLY recommended.
> ****************************************************************************
> Warning! Main partition table overlaps the first partition by 33 blocks!
> You will need to delete this partition or resize it in another utility.
> Disk /dev/sdc: 11721045168 sectors, 5.5 TiB
> Model: WDC WD60EFRX-68M
> Sector size (logical/physical): 512/4096 bytes
> Disk identifier (GUID): FC86A481-0709-11E7-B298-3464A99AF244
> Partition table holds up to 128 entries
> Main partition table begins at sector 2 and ends at sector 33
> First usable sector is 34, last usable sector is 11721045134
> Partitions will be aligned on 8-sector boundaries
> Total free space is 11721045101 sectors (5.5 TiB)
> 
> Number  Start (sector)    End (sector)  Size       Code  Name
>   69               1               6   3.0 KiB     FFFF  윜㺗ᣲ䌟犔熵䕭㶖Ẑ坔
> 
> 
> Any ideas what's happened here seeing as both drives appear to suffer
> the same symptoms and what I can do to attempt a recovery?
> 


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