[SOLVED] Can't mount encrypted Mint HDD on Raspberry Pi 3 as external drive

radarvideolocust · 05-13-2016, 03:38 AM

Hi, folks! I had a laptop running Linux Mint with an encrypted hard drive. The laptop had a hardware failure and will not boot, but the disk should be 100% fine. I currently have it in a caddy that converts it into an external drive via USB, and I'm trying to view its contents on my Raspberry Pi 3 running Raspbian.

When I plug the drive into my Pi, I get the usual GUI window prompting me for a password, and upon entering the password and clicking "connect", I get an error window stating "Error unlocking /dev/sda5: Command-line `cryptsetup luksOpen "/dev/sda5" "luks-f1cb848f-5d8e-4c40-9865-ba43ee8cd878"' exited with non-zero exist status 1:"

When I run "sudo cryptsetup luksOpen /dev/sda5 test_name", I get a new file /dev/dm-0, which seems like a step in the right direction, but then "udisksctl mount -b /dev/sda5" gives me the error "Object /org/freedesktop/UDisks2/block_devices/sda5 is not a mountable filesystem."

It seems to me that, if I had a working machine that would fit a 2.5" hard drive in it, I could swap it out and boot it just like on my old laptop, but I'd like to be able to access these files without buying a new machine.

Thus far, the only contents it shows me for the disk seem to be boot-related stuff, as if I had opened a liveUSB device, but I can't see the contents that I'd be able to get to had I booted from it. I need to get access to the user-level files, so any help would be appreciated.

Code:

pi@raspberrypi://media/pi/c0f936b6-40a0-4294-b103-e3fbce9aac80 $ ls
abi-3.13.0-37-generic         lost+found
abi-3.19.0-32-generic         memtest86+.bin
abi-4.2.0-25-generic          memtest86+.elf
config-3.13.0-37-generic      memtest86+_multiboot.bin
config-3.19.0-32-generic      System.map-3.13.0-37-generic
config-4.2.0-25-generic       System.map-3.19.0-32-generic
grub                          System.map-4.2.0-25-generic
initrd.img-3.13.0-37-generic  vmlinuz-3.13.0-37-generic
initrd.img-3.19.0-32-generic  vmlinuz-3.19.0-32-generic
initrd.img-4.2.0-25-generic   vmlinuz-4.2.0-25-generic

Code:

pi@raspberrypi:~ $ sudo lvdisplay
  --- Logical volume ---
  LV Path                /dev/mint-vg/root
  LV Name                root
  VG Name                mint-vg
  LV UUID                zeTEgH-oz7f-7zGC-mr9f-MV8M-mKyv-1Hfqfg
  LV Write Access        read/write
  LV Creation host, time mint, 2015-01-11 03:42:02 +0500
  LV Status              NOT available
  LV Size                294.09 GiB
  Current LE             75288
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
   
  --- Logical volume ---
  LV Path                /dev/mint-vg/swap_1
  LV Name                swap_1
  VG Name                mint-vg
  LV UUID                d78cto-VHjD-jqFb-PKNH-hl56-bz5h-PYqQT0
  LV Write Access        read/write
  LV Creation host, time mint, 2015-01-11 03:42:02 +0500
  LV Status              NOT available
  LV Size                3.74 GiB
  Current LE             957
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto

mostlyharmless · 05-13-2016, 03:10 PM

It seems to me that after you open your encrypted partition with cryptsetup, you need to open the lvm container. You'll need to do vgscan --mknodes and vgchange -ay, then check in /dev/mapper for the presumably new entries you can mount with mount.

radarvideolocust · 05-13-2016, 06:09 PM

Wow, this had been a thorn in my side for a long time, and I'd spent hours Googling around trying to fix it, so thanks a heap for the solution!

Further info for anyone else with the same issue: Using "vgscan --mknodes" gave me the name of the volume group (mint-vg), which contains two volumes (root and swap-1), and then I mounted it with

Code:

mount /dev/mint-vg/root /mnt

And the resulting files are in /mnt/