How can I read files from /dev/sdc

Ubuntu
21

I’m so sorry that my correction to my suggestion was too late :frowning:

Unfortunately inspecting dmesg is more complex, these first lines tell only about very early booting the system, that does not give any info about your issue.
Dmesg is usually very long.
Whenever I expect an operation to put something in kernel log, I start dmesg -w from a root console, and I execute the thing to trigger the problem.
Shortly after that stop dmesg -w, so there will be only few lines to inspect.
So the interesting info from dmesg will be on the lines that appeared right after you issued the mount command, that’s near the end of dmesg, not at the start of it.

Back to your problem:
So you did run fsck, it applied some fixes to the filesystem, and it is now mounted.
Right?
If that’s the case, copy the data you can salvage as soon as possible.
As for the other disk, there’s probably only the Photorec method left.
Don’t you have any clue about LVM? Does this sound familiar for you?
(I just try to estimate the chances you had an LVM setup).

For all other forum members: Does Ubuntu provide some automation, that would create LVM grouped disk usage upon install, probably even without the knowledge of the user?

Can we have an idea, what you would like to recover?
Family photos, or documents? Anything unreproduceable?

22

Most installers ask if you want LVM.
It would be easy for a user to say yes, without realising what they were doing

23

I’m just installing Ubuntu 22.04 on a dual disk VM.
I opted only for defaults.
Soon we’ll see the disk layout it gives…

Képernyőkép – 2024-01-23 13-46-27
Képernyőkép – 2024-01-23 13-46-271920×1080 157 KB

I can’t wait to see it…

So the all-default setup left the second disk untouched.

24

If you had chosen LVM, what would have happened?

BTW How did you come to guess that LVM might be present?

25

Just trying that…

Képernyőkép – 2024-01-23 14-03-40
Képernyőkép – 2024-01-23 14-03-401920×1080 207 KB

26

I’ve read back the topic.

I’m still not sure that LVM is really involved, as something very weird was going on there.
But maybe the LVM was there, and I should have noticed it sooner, on the first less-truncated parted -l output… :frowning:

27

Sun is a valid partition table type

But why would Rodney have a Sun Workstation disk?
Is sdc maybe a secondhand disk?

28

My advice for @Rodney_Jackson is to find a disk caddy and pull every disk except the boot drive and see if the disks will open, via usb from the disk caddy. This works for when I want to retrieve data from a disk without installing the disk.

29

I doubt he really has it. Something got seriously messed up there.

I installed Ubuntu 2 times onto that VM, nothing changed during install, except I choosed LVM.
The second disk seems to be untouched and empty again.
However, I cannot login on that Ubuntu machine, my user is not listed on the login screen :smiley:

Stopping Ubuntu, and adding those virtual disks to an other VM with Linux Mint:
blkid shows there clearly that it’s about LVM, whereas lsblk just mention sdb alone, appearing as an unused empty disc.

root@kl-VirtualBox:/home/kl# blkid
/dev/mapper/vgubuntu-swap_1: UUID="128d772d-71eb-4d08-9f53-a87ba0cf787c" TYPE="swap"
/dev/sr0: BLOCK_SIZE="2048" UUID="2024-01-15-14-48-13-93" LABEL="VBox_GAs_7.0.14" TYPE="iso9660"
/dev/mapper/vgubuntu-root: UUID="1ef1fe4a-df5d-418b-9e4a-b6c951ecc3e9" BLOCK_SIZE="4096" TYPE="ext4"
/dev/sdc2: UUID="541E-65C5" BLOCK_SIZE="512" TYPE="vfat" PARTUUID="d5847397-7c14-4a33-ac78-dee37f4c5597"
/dev/sdc3: UUID="MFfg3k-mFAP-wmXT-0UnL-KLn2-nEnr-dcg4us" TYPE="LVM2_member" PARTUUID="66dc301f-4df7-4b97-9807-17cd67c2b151"
/dev/sda2: UUID="8EF6-60B5" BLOCK_SIZE="512" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="7bd0eb83-868b-4a00-ac85-64e4bb95fd4d"
/dev/sda3: UUID="8c8522ef-2fb9-4ff8-838a-ba1e72da589c" BLOCK_SIZE="4096" TYPE="ext4" PARTUUID="c4eb38b8-4501-4f10-bb63-b8618fcf4893"
/dev/sdc1: PARTUUID="cebbf60d-bab0-417e-bb33-2f69f99f9ce0"
/dev/sda1: PARTUUID="dc830ad9-d915-444d-a87f-62db12a0ddae"
root@kl-VirtualBox:/home/kl# lsblk
NAME                MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda                   8:0    0   41G  0 disk 
├─sda1                8:1    0    1M  0 part 
├─sda2                8:2    0  513M  0 part /boot/efi
└─sda3                8:3    0 40,5G  0 part /
sdb                   8:16   0 49,9G  0 disk 
sdc                   8:32   0 31,6G  0 disk 
├─sdc1                8:33   0    1M  0 part 
├─sdc2                8:34   0  513M  0 part 
└─sdc3                8:35   0 31,1G  0 part 
  ├─vgubuntu-root   253:0    0 27,9G  0 lvm  
  └─vgubuntu-swap_1 253:1    0  3,2G  0 lvm  
sr0                  11:0    1   51M  0 rom  /media/kl/VBox_GAs_7.0.14
1 Like
30

It looks quite different to what we get with Rodney’s disk
He does not seem to have LVM… he has some other issue

Agree.

What could we use to look at that sdc disk?
We need to know reliably what its structure is.
Do you think dd would copy it? Maybe a loop mount?
Would gparted tell us anything?

Rodney did not try to mount sdc1 or sdc3
Should he try a mount without specifying filesystem type.?
Linux may be able to autodetect it.

31

The above is the second command not “mount /dev/sdc/sssdc”

1 Like
32

Hi Neville and Laszlo, I tried both sudo mount… and also mount… without sudo, both advised “command not found”. At this point I think I might have to reformat both sdb and sdc and start again from scratch. You have both put in a lot of examples and tests, my box here just does not want to play fair.

I truly appreciate both your inputs and I feel guilty that nothing works here.

I think we shall put this down to a lost cause.

Kind regards,
Rod.

1 Like
33

Hi Rodney,
Your choice.
We are still able to help if you wish.

You will get that if you try a mount without sudo
but
it is strange that sudo mount .... returned that message.
Are you sure you did it right?

Regards
Neville

34

hello Neville, yes I checked everything when I get an error message.
Rod

1 Like
35

dd copies anything, unless the the source disk is unreadbable. So dd-ing it to another disk or to an image surely would work, however, the result is going to be useless just like the source.

He tried it, it did not work.

I’d definitely go for testdisk:

Maybe it could recover the filesystem.
If not (chances are), I’d try to recover precious data with Photorec.
That scans the data on the whole disc, and tries to find documents, images, videos etc. based on the data structure it reads from the physical sectors, so it may recover lost files regardless of the filesystem it stored them before, and regardless how much damage the filesystem itself got…
So the filenames arent fully recovered, only the data, including data from files deleted long before (but still not physically overwritten).

Once I succesfully recovered a whole days recording from an accidentally formatted and partially overwitten SD card. So what Photorec can do is sometimes life- and ass-saving and invaluable.

If those drive don’t contain data that worth the work to recover this way, I’d just repartition, and reformat those disks to make use of them.

You aren’t guilty!

If we want to find the cause, the error message has to be noted as precise as possible. :wink:
The “mount” should be there for a regular user (not root) too, without any parameter it lists the current mounts.
If you recieve “command not found” message, that most probably means you mistyped the command.
I frequently change the order of letters as I type, and I could write “muont” instead of “mount”. This kind typo is very-very hard to spot for myself, for example I can spend dozens of minutes to find where I did such mistake in a script I’m writing.

So when someone gives you commands to enter into the terminal, better copy/paste it.
Select the command here from the text, copy to clipboard -say press ctrl-C.
Then go to the terminal, and paste there, say press ctrl-shift-V.
There are other methods too, but this surely works.
So you can avoid your own typos.

2 Likes
36

Hello Neville, Laszlo, et-al. Sorry for not answering for a while, things went really pear shape and I had to reinstall ubuntu 22.04. I couldn’t use the Terminal, couldn’t get email to work, even email went on the fritz. I guess now, I will have to close this subject. Sincerely thank you all for your tireless help, it is really appreciated. I would love to have known what program messed things up, however, this time at least, I have missed out.
Rod.

2 Likes
37

Rodney, do you make regular backups.?
It is important to do that , so you can recover from disasters
without having to reinstall from scratch.