I can't backup ext4 logical volume, it can't mount

dora123 · 01-15-2022, 03:59 AM

My dedicate server has 1 ssd (sda) and 1 hdd (sdb), I want to backup vg-root volume with fsarchiver by booting with rescuedsystem. but it can't mount vg-root with "wrong fs type, bad option, bad superblock on ..."

when use fsarchiver , it can't mount too.
so it's possible that are there problem in vg-root or not? how can I mount and backup this volume.

see details in this picture.
https://i.ibb.co/5Lj0yWp/cannotmount3.jpg

Brains · 01-16-2022, 03:24 AM

Quote:

mount /dev/vg/root

This appears incorrect according to the error message:

Quote:

bad superblock on /dev/mapper/vg-root

Try running fsck on the partition before mounting it like so:

Code:

mount -t ext4 /dev/mapper/vg-root

Tonus · 01-16-2022, 03:46 AM

Could it be an encrypted volume ?

dora123 · 01-17-2022, 12:21 AM

mount -t ext4 /dev/mapper/vg-root
mount: wrong fs type, bad option, bad superblock on /dev/mapper/vg-root,
missing codepage or helper program, or other error

In some cases useful info is found in syslog - try
dmesg | tail or so.

But the strange that when boot in syscd it can't mount vg-root but when boot in ubuntu it mount as /
but still can't use fsarchiver to backup, same error.

syg00 · 01-17-2022, 12:46 AM

Quote:

Originally Posted by dora123

In some cases useful info is found in syslog - try
dmesg | tail or so.

And ?.

lvm_ · 01-17-2022, 03:14 AM

Actually there is no need too boot from a separate media. You can back up live LVM volumes using snapshotting e.g. check this tutorial https://www.system-rescue.org/lvm-gu...kups-with-LVM/

rknichols · 01-17-2022, 09:45 AM

Perhaps your sysresccd has an older kernel that doesn't support some feature in your current ext4 filesystem, and you just need a newer sysresccd.

From your sysresccd, let's see the output from "uname -r" and "tune2fs -l /dev/vg/root | grep features".

dora123 · 01-19-2022, 03:56 AM

Quote:

Originally Posted by rknichols

Perhaps your sysresccd has an older kernel that doesn't support some feature in your current ext4 filesystem, and you just need a newer sysresccd.

From your sysresccd, let's see the output from "uname -r" and "tune2fs -l /dev/vg/root | grep features".

after change sysrcd from 4.3 to 5.0 , the problem solve.

thank