[CentOS] C7 live CD does not like F33 ext partition

Wed Apr 21 01:19:47 UTC 2021
Michael Hennebry <hennebry at web.cs.ndsu.nodak.edu>

On Tue, 20 Apr 2021, Michael Hennebry wrote:

> I've been trying to backup the root partition of my F33 installation.
> To that end, I'm running a C7 live CD.
> C7 won't mount the partition.
> tune2fs likes it, but
> [root at localhost mnt]# mount /dev/sda5 /mnt/a5
> mount: wrong fs type, bad option, bad superblock on /dev/sda5,
>       missing codepage or helper program, or other error
>       In some cases useful info is found in syslog - try
>       dmesg | tail or so.
> [root at localhost mnt]# dmesg | tail -n 15

> [  146.548540] Bluetooth: BNEP socket layer initialized
> [  300.961319] JBD2: Unrecognised features on journal
> [  300.961325] EXT4-fs (sda5): error loading journal   ====== WHY?
> [  361.930877] e1000e: enp0s25 NIC Link is Up 1000 Mbps Full Duplex, Flow

I just ran fsck -n /dev/sda5 .
[root at localhost mnt]# fsck -n /dev/sda5
fsck from util-linux 2.23.2
e2fsck 1.42.9 (28-Dec-2013)
Journal superblock has an unknown incompatible feature flag set.
Abort? no

Journal superblock is corrupt.
Fix? no

fsck.ext4: The ext2 superblock is corrupt while checking ext3 journal for slash

slash: ********** WARNING: Filesystem still has errors **********

[root at localhost mnt]#

What is going on?
What can I do about it?

Does "unknown incompatible feature flag set" imply corrupt?
How dangerous would it be to let fsck fix it?

I'm starting to think I might need to back up / while it is in use.

Michael   hennebry at web.cs.ndsu.NoDak.edu
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