Re: [gentoo-user] data recovery advice needed

[Grant Taylor <gtaylor@gentoo.tnetconsulting.net>]

On 12/19/2018 04:43 AM, Mick wrote:
> I ran ddrescue while the drive was still on the laptop.  The clone was on the
> USB caddy.

ACK

> The disk block device is there and so is the first partition (only):
> 
> ls -la /dev/sdb*
> brw-rw---- 1 root disk 8, 16 Dec 19 11:20 /dev/sdb
> brw-rw---- 1 root disk 8, 17 Dec 19 11:20 /dev/sdb1
> 
> However, there's 6 partitions in total:
> 
> Disk /dev/sdb: 1953525168 sectors, 931.5 GiB
> Model: LucidPort USB300
> Sector size (logical/physical): 512/512 bytes
> Disk identifier (GUID): 1A95F5D1-5630-4E06-9DC3-36841C786DDF
> Partition table holds up to 128 entries

128 entries tells me that the disk has GPT partition table, not a 
classis MS-DOS / PC-BIOS partition table.

This sounds like the (what I understand to be) the classic protection 
partition that GPT fakes in PC-BIOS partition tables.

Do you have GPT partition support in your kernel?

I'm guessing the one partition that you see is the size of the entire drive.

> Main partition table begins at sector 2 and ends at sector 33
> First usable sector is 34, last usable sector is 1953525134
> Partitions will be aligned on 2048-sector boundaries
> Total free space is 4770 sectors (2.3 MiB)
> 
> Number  Start (sector)    End (sector)  Size       Code  Name
>     1            2048          821247   400.0 MiB   2700  Basic data partition
>     2          821248         1353727   260.0 MiB   EF00  EFI system partition
>     3         1353728         1615871   128.0 MiB   0C01  Microsoft reserved
> ...
>     4         1615872      1911737034   910.8 GiB   0700  Basic data partition
>     5      1911738368      1915412479   1.8 GiB     2700
>     6      1915412480      1953523711   18.2 GiB    0700  Basic data partition
> 
> I can see partition 4 I was trying to recover, but could not add it:
> 
> partx --show --nr 4 /dev/sdb
> NR   START        END    SECTORS   SIZE NAME                 UUID
>   4 1615872 1911737034 1910121163 910.8G Basic data partition fea85fb3-
> cfdb-4868-a1ad-bab264dad237
> 
> partx --add --nr 4 /dev/sdb
> partx: /dev/sdb: error adding partition 4
> 
> partx --add /dev/sdb
> partx: /dev/sdb: error adding partitions 1-6

That really sounds like your kernel doesn't have GPT support (loaded).

> In any case, losetup with offset/size succeeded in mounting it and I was able
> to access the fs on it.

Good.



-- 
Grant. . . .
unix || die