How to easily mount, inspect, unmount and delete LVM volumes manually ? (solution)

[shodan]

Hi,

I have an old broken proxmox system, with a few good VMs and CTs to save and a bunch that I don't remember what they are...

So I need an easy way to mount them and unmount them.

And I didn't want to inspect them on what was inside, just single command that takes care of sole partitions or multiple partition volumes.


So far I came up with this

mounting

mountlvm() { LVFULL="$1"; losetup -D; fdisk -l "/dev/$LVFULL"; LOOP=$(losetup --find --show "/dev/$LVFULL"); partx -l "$LOOP" &>/dev/null && partx -a "$LOOP"; for DEV in "$LOOP" ${LOOP}p*; do TYPE=$(blkid -s TYPE -o value "$DEV"); [ "$TYPE" = "swap" ] || [ -z "$TYPE" ] && continue; MNT="/mnt/${LVFULL//\//,}${DEV#$LOOP}"; mkdir -p "$MNT" && mount "$DEV" "$MNT" && echo "Mounted $DEV to $MNT"; done; }

unmounting

umountlvm() { LVFULL="$1"; LOOP=$(losetup -j "/dev/$LVFULL" | head -n1 | cut -d: -f1); for DEV in "$LOOP" ${LOOP}p*; do MNT="/mnt/${LVFULL//\//,}${DEV#$LOOP}"; mountpoint -q "$MNT" && umount "$MNT" && rmdir "$MNT" && echo "Unmounted $DEV from $MNT"; done; partx -d "$LOOP" 2>/dev/null; losetup -d "$LOOP"; }

Here is how that works for a single filesystem in an lvm

root@proxmox:/mnt# mountlvm thinvg/vm-101-disk-0
Disk /dev/thinvg/vm-101-disk-0: 64 GiB, 68719476736 bytes, 134217728 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 524288 bytes / 524288 bytes
Mounted /dev/loop0 to /mnt/thinvg,vm-101-disk-0
root@proxmox:/mnt# ls
thinvg,vm-101-disk-0
root@proxmox:/mnt# ls thinvg,vm-101-disk-0/
BepInEx  boot  etc   just_start_valheim.sh  lib32  lost+found  mnt  proc  run   srv                         sys  usr      valheim-mods-download  var
bin      dev   home  lib                    lib64  media       opt  root  sbin  start_modded_flisholand.sh  tmp  valheim  valheim_worlds
root@proxmox:/mnt# umountlvm $LVFULL
Unmounted /dev/loop0 from /mnt/thinvg,vm-101-disk-0
root@proxmox:/mnt#

and here is how that works for a partition table in the lvm

root@proxmox:/mnt# mountlvm thinvg/vm-110-disk-1
Disk /dev/thinvg/vm-110-disk-1: 32 GiB, 34359738368 bytes, 67108864 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 524288 bytes / 524288 bytes
Disklabel type: gpt
Disk identifier: FC845519-5018-45E5-A622-CB46D0C0D52D

Device                        Start      End  Sectors  Size Type
/dev/thinvg/vm-110-disk-1p1    2048  1026047  1024000  500M EFI System
/dev/thinvg/vm-110-disk-1p2 1026048  1288191   262144  128M Microsoft reserved
/dev/thinvg/vm-110-disk-1p3 1288192  2312191  1024000  500M Windows recovery environment
/dev/thinvg/vm-110-disk-1p4 2312192 67106815 64794624 30.9G Microsoft basic data
Mounted /dev/loop0p1 to /mnt/thinvg,vm-110-disk-1p1
Mounted /dev/loop0p3 to /mnt/thinvg,vm-110-disk-1p3
Mounted /dev/loop0p4 to /mnt/thinvg,vm-110-disk-1p4
root@proxmox:/mnt# ls
thinvg,vm-110-disk-1p1  thinvg,vm-110-disk-1p3  thinvg,vm-110-disk-1p4
root@proxmox:/mnt# ls thinvg,vm-110-disk-1p1/
 EFI  'System Volume Information'
root@proxmox:/mnt# ls thinvg,vm-110-disk-1p3/
'System Volume Information'
root@proxmox:/mnt# ls thinvg,vm-110-disk-1p4/
'$Recycle.Bin'             DumpStack.log.tmp   PerfLogs     'Program Files'         Recovery      'System Volume Information'   Windows
'Documents and Settings'   pagefile.sys        ProgramData  'Program Files (x86)'   swapfile.sys   Users
root@proxmox:/mnt# df -h  | grep 110
/dev/loop0p1          496M   27M  470M   6% /mnt/thinvg,vm-110-disk-1p1
/dev/loop0p3          500M   13M  488M   3% /mnt/thinvg,vm-110-disk-1p3
/dev/loop0p4           31G   13G   18G  42% /mnt/thinvg,vm-110-disk-1p4
root@proxmox:/mnt# umountlvm $LVFULL
Unmounted /dev/loop0p1 from /mnt/thinvg,vm-110-disk-1p1
Unmounted /dev/loop0p3 from /mnt/thinvg,vm-110-disk-1p3
Unmounted /dev/loop0p4 from /mnt/thinvg,vm-110-disk-1p4
root@proxmox:/mnt# ls
root@proxmox:/mnt# df -h  | grep 110
root@proxmox:/mnt#

This won't mount swap partition

It's not perfect however, it doesn't seem to work with EFIDISKS

EFIDISKS, not mounting

root@proxmox:/mnt# mountlvm thinvg/vm-110-disk-0
Disk /dev/thinvg/vm-110-disk-0: 4 MiB, 4194304 bytes, 8192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 524288 bytes / 524288 bytes
root@proxmox:/mnt# ls
root@proxmox:/mnt# umountlvm $LVFULL
root@proxmox:/mnt# fdisk -l /dev/thinvg/vm-110-disk-0
Disk /dev/thinvg/vm-110-disk-0: 4 MiB, 4194304 bytes, 8192 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 524288 bytes / 524288 bytes
root@proxmox:/mnt# blkid /dev/thinvg/vm-110-disk-0

Also in the example with partition above, the partition
/dev/thinvg/vm-110-disk-1p2 1026048 1288191 262144 128M Microsoft reserved
did not mount


But still this was good enough for me for now !
I hope this is useful to you !