Error mounting /dev/sdb7

[MibunoOokami]

Hello everyone, sorry for the long post,

I got a call last night from a distressed friend who did a window$ update and can't access Ubuntu anymore. Having put their mind at ease letting them know it'll be as simple as making a backup and then updating grub, I brought the machine to my place to begin the work. I have included output from some troubleshooting tips on another (solved) thread with a similar problem. The aforementioned thread is a little difficult for me to follow as the issue looks somewhat different. It indicates filesystem check/repair is required, there's only so many things I'm happy to try without being able to back up the machine.

Upon booting up with a live CD and attempting to first open the partition that needs backing up, I have been greeted with the following error, which I have never seen before. I've tried troubleshooting this myself and am not having much luck. I really would appreciate any

Error mounting /dev/sdb7 at /media/ubuntu/64de21bd-d4ab-467e-91ea-e3695662b11f: Command-line `mount -t "ext4" -o "uhelper=udisks2,nodev,nosuid" "/dev/sdb7" "/media/ubuntu/64de21bd-d4ab-467e-91ea-e3695662b11f"' exited with non-zero exit status 32: mount: wrong fs type, bad option, bad superblock on /dev/sdb7, 
       missing codepage or helper program, or other error 
       In some cases useful info is found in syslog - try 
       dmesg | tail  or so

The output of dmesg | tail doesn't mean anything to me. I don't want to have to eat my words and say getting the grub menu back isn't as simple as I said, so I would really appreciate your help in finding out what is going on and how to resolve this problem. Thanks in advance.

ubuntu@ubuntu:~$ dmesg | tail 
[  338.800164] end_request: I/O error, dev sr0, sector 859944 
[  356.188410] JBD2: Unrecognised features on journal 
[  356.188417] EXT4-fs (sdb7): error loading journal 
[  504.625872] wlan0: authenticate with a4:91:b1:44:4b:8d 
[  504.646266] wlan0: send auth to a4:91:b1:44:4b:8d (try 1/3) 
[  504.648222] wlan0: authenticated 
[  504.653088] wlan0: associate with a4:91:b1:44:4b:8d (try 1/3) 
[  504.657194] wlan0: RX AssocResp from a4:91:b1:44:4b:8d (capab=0x1411 status=0 aid=1) 
[  504.657261] wlan0: associated 
[  504.657306] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready

ubuntu@ubuntu:~$ sudo parted -l 
Model: ATA WDC WD10JPVX-22J (scsi) 
Disk /dev/sdb: 1000GB 
Sector size (logical/physical): 512B/4096B 
Partition Table: gpt 
 
Number  Start   End     Size    File system  Name                          Flags 
 1      1049kB  524MB   523MB   ntfs         Basic data partition          hidden, diag 
 2      524MB   629MB   105MB   fat32        EFI system partition          boot 
 3      629MB   646MB   16.8MB               Microsoft reserved partition  msftres 
 4      646MB   53.3GB  52.7GB  ntfs         Basic data partition          msftdata 
 5      53.3GB  53.9GB  512MB   fat32                                      boot 
 6      53.9GB  85.5GB  31.6GB  ext4 
 7      85.5GB  1000GB  915GB   ext4 
 
 
Warning: Unable to open /dev/sr0 read-write (Read-only file system).  /dev/sr0 
has been opened read-only. 
Error: Can't have a partition outside the disk!

ubuntu@ubuntu:~$ cat /etc/fstab 
overlayfs / overlayfs rw 0 0 
tmpfs /tmp tmpfs nosuid,nodev 0 0

Again, I would really appreciate your help with this. Thank you in advance.

[HermanAB]

It looks to me as if one of the ext4 disk partitions /dev/sr0 is corrupted.

[MibunoOokami]

It looks to me as if one of the ext4 disk partitions /dev/sr0 is corrupted.

Isn't that the optical drive? I'm using a physical CD rather than USB because I seem to recall issues getting it to recognise a USB. The CD itself shouldn't be corrupt as I have used it for installing Ubuntu in the past, so could it be the optical drive is failing and causing this problem?

[westie457]

Maybe the info here might be of some help. https://ubuntuforums.org/showthread....7#post13171637

[MibunoOokami]

Maybe the info here might be of some help. https://ubuntuforums.org/showthread....7#post13171637

If I understand correctly, nothing (backup) can be done before doing a disk check? So there's potentially a risk of data being lost through this process?

Edit: Or is it I just don't need to use -y or -p, then I will be asked if want to fix if a problem is found, and can potentially say no? Although I guess that won't be very helpful to do.

Edit: Would the window$ update have been responsible for this?

[MibunoOokami]

After securing permission from the owner to go ahead and try resolve this without being able to do a backup, I ran the command

fdisk -l

and this is the output

ubuntu@ubuntu:~$ sudo fdisk -l 
 
WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted. 
 
 
Disk /dev/sda: 8388 MB, 8388608000 bytes 
255 heads, 63 sectors/track, 1019 cylinders, total 16384000 sectors 
Units = sectors of 1 * 512 = 512 bytes 
Sector size (logical/physical): 512 bytes / 512 bytes 
I/O size (minimum/optimal): 512 bytes / 512 bytes 
Disk identifier: 0x663eb4c4 
 
   Device Boot      Start         End      Blocks   Id  System 
/dev/sda1   *           0     3815135     1907568    0  Empty 
/dev/sda2         3737268     3741939        2336   ef  EFI (FAT-12/16/32) 
 
WARNING: GPT (GUID Partition Table) detected on '/dev/sda1'! The util fdisk doesn't support GPT. Use GNU Parted. 
 
 
Disk /dev/sda1: 1953 MB, 1953349632 bytes 
255 heads, 63 sectors/track, 237 cylinders, total 3815136 sectors 
Units = sectors of 1 * 512 = 512 bytes 
Sector size (logical/physical): 512 bytes / 512 bytes 
I/O size (minimum/optimal): 512 bytes / 512 bytes 
Disk identifier: 0x663eb4c4 
 
     Device Boot      Start         End      Blocks   Id  System 
/dev/sda1p1   *           0     3815135     1907568    0  Empty 
/dev/sda1p2         3737268     3741939        2336   ef  EFI (FAT-12/16/32) 
 
WARNING: GPT (GUID Partition Table) detected on '/dev/sdc'! The util fdisk doesn't support GPT. Use GNU Parted. 
 
 
Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes 
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors 
Units = sectors of 1 * 512 = 512 bytes 
Sector size (logical/physical): 512 bytes / 4096 bytes 
I/O size (minimum/optimal): 4096 bytes / 4096 bytes 
Disk identifier: 0x45098b5c 
 
   Device Boot      Start         End      Blocks   Id  System 
/dev/sdc1               1  1953525167   976762583+  ee  GPT 
Partition 1 does not start on physical sector boundary.

I don't know what to make of this, shouldn't I be seeing /dev/sdb in here?

[MibunoOokami]

I don't know what to make of this, shouldn't I be seeing /dev/sdb in here?

Okay, and the output of sudo e2fsck -C0 -p -f -v /dev/sdb7

ubuntu@ubuntu:~$ 
 e2fsck: No such file or directory while trying to open /dev/sdb7 
 Possibly non-existent device?

and trying again with sudo e2fsck -C0 -p -f -v /dev/sdb

ubuntu@ubuntu:~$ sudo e2fsck -C0 -p -f -v /dev/sdb 
 e2fsck: No medium found while trying to open /dev/sdb 
 /dev/sdb:  
 The superblock could not be read or does not describe a valid ext2/ext3/ext4 
 filesystem.  If the device is valid and it really contains an ext2/ext3/ext4 
 filesystem (and not swap or ufs or something else), then the superblock 
 is corrupt, and you might try running e2fsck with an alternate superblock: 
     e2fsck -b 8193 <device> 
  or 
     e2fsck -b 32768 <device>

Am I right in thinking this is a very serious problem with my friend's machine? Is it fixable?

[MibunoOokami]

FWIW, evidently for the past six months or so Ubuntu had been freezing every other day, so my friend would have to do a forced reboot/shutdown to resolve that issue. I'm told the computer was being used throughout the day, but this problem of freezing happened predominantly at night.

[Bashing-om]

MibunoOokami; Ouch !

This could be a real tough nut to crack.

What drives are seen in bios when booting ?
If all drives are seen hardware wise we can then start at the bottom and see what we can work out,
What operating system and on which drive are you booting ?

Else:
Do you have a liveUSB onhand ?

see what might be done

[MibunoOokami]

MibunoOokami; Ouch !

This could be a real tough nut to crack.

What drives are seen in bios when booting ?
If all drives are seen hardware wise we can then start at the bottom and see what we can work out,
What operating system and on which drive are you booting ?

Else:
Do you have a liveUSB onhand ?

see what might be done

Ooh I got bad news about BIOS... It's PW protected and the owner doesn't know what it is, so don't know what drives are seen. I have a live USB good to go, but need access to BIOS. Not sure how much difference there is, but I am able to use a LiveCD instead with no issues.

The OS I believe to be Windows 7 or 10, couldn't tell you which drive is booting.

EDIT: So it's probably a good thing i didn't dive straight in and play with Testdisk?