Can't see mounted drive under lsblk, blkid or mount

Question

I have mounted an external hard drive via /etc/fstab with the following entry:

UUID=a8286fc9-5b08-41d9-8c4e-cb993a8976d1 /home/bu/safe-heaven-2/ ext4 defaults 0

I can read/write from this disk but I have some issues related to making backups via backintime (see below). So I started to poke around and see if I can find out anything but for some reason, I cannot see this drive with any of the commands mount, blkid or lsblk. So I am stuck. What can be the reason for this?

The 'actual' issue at hand: This is a new 2TB drive I use for making backups but for some reason backintime keeps telling me that the disk is full at some point. This can't be true as I am trying to (partially) back up a disk that is only 1TB big and by no means full.

When I try to do a fsck /home/bu/safe-heaven-2 on this disk, I get the following error:

fsck.ext4: Unable to resolve 'UUID=a8286fc9-5b08-41d9-8c4e-cb993a8976d1'

But as I wrote, I can read / write to this disk. I am totally confused :D Please help!

Edit: Output of fdisk -l as requested:

Disk /dev/ram0: 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): 4096 bytes / 4096 bytes


Disk /dev/ram1: 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): 4096 bytes / 4096 bytes


Disk /dev/ram2: 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): 4096 bytes / 4096 bytes


Disk /dev/ram3: 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): 4096 bytes / 4096 bytes


Disk /dev/ram4: 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): 4096 bytes / 4096 bytes


Disk /dev/ram5: 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): 4096 bytes / 4096 bytes


Disk /dev/ram6: 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): 4096 bytes / 4096 bytes


Disk /dev/ram7: 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): 4096 bytes / 4096 bytes


Disk /dev/ram8: 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): 4096 bytes / 4096 bytes


Disk /dev/ram9: 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): 4096 bytes / 4096 bytes


Disk /dev/ram10: 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): 4096 bytes / 4096 bytes


Disk /dev/ram11: 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): 4096 bytes / 4096 bytes


Disk /dev/ram12: 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): 4096 bytes / 4096 bytes


Disk /dev/ram13: 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): 4096 bytes / 4096 bytes


Disk /dev/ram14: 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): 4096 bytes / 4096 bytes


Disk /dev/ram15: 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): 4096 bytes / 4096 bytes


Disk /dev/mmcblk0: 14,9 GiB, 15931539456 bytes, 31116288 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
Disklabel type: dos
Disk identifier: 0x1ddfbf63

Device         Boot  Start      End  Sectors  Size Id Type
/dev/mmcblk0p1        8192   532479   524288  256M  c W95 FAT32 (LBA)
/dev/mmcblk0p2      532480 31116287 30583808 14,6G 83 Linux


Disk /dev/sdb: 931,5 GiB, 1000170586112 bytes, 1953458176 sectors
Disk model: Elements 10A8   
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x07e93288

Device     Boot Start        End    Sectors   Size Id Type
/dev/sdb1        2048 1953458175 1953456128 931,5G 83 Linux

Have you tried `lsblk -f`, `fdisk -x`, or `lsblk -O | less -S`? They might show more information. If that program reports that the disk is full, that might be due to how it is partitioned (1TB partition) and also due to the filesystem used (check [Limits](https://en.wikipedia.org/wiki/Comparison_of_file_systems#Limits)). — Vilinkameni, Oct 20 '21 at 04:47

Vlastimil Burián · Answer 1 · 2021-10-20T04:16:02.090

0

You can never fsck-repair a mountpoint, what's more - the scanned partition must be UNMOUTED for fsck not to cause more harm than good.

So, unmount it first, and then do:

fsck -fn /dev/disk/by-uuid/...

If some errors are found, and you want to fix all of them, then afterward:

fsck -fy /dev/disk/by-uuid/...

Also to note that there are other options than UUID, just hit double tab with /dev/disk/by- to know them all.

There are these options:

by-id/
by-label/
by-partlabel/
by-partuuid/
by-path/
by-uuid/

If not found there

Try to examine the system message log:

dmesg

for example you should start with:

dmesg | grep sda

as I can see /dev/sdb is present in fdisk -l but /dev/sda not, or more info with:

dmesg | grep sd

But if Elements 10A8 is your drive you can't find, then search for sdb.

edited Oct 20 '21 at 04:16

answered Oct 19 '21 at 18:08

Vlastimil Burián

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According to the [man](https://linux.die.net/man/8/fsck) page, you can `fsck` a mount point. You shouldn't make any changes to the file system while it is mounted. – doneal24 Oct 19 '21 at 18:11
`fsck` was just another attempt on trying to find out what is going on. I don't necessarily want to fix the disk. The disk also doesn't show up under any of the /dev/... folders. – password is password Oct 19 '21 at 18:46
@passwordispassword updated, look into `dmesg` for some traces. – Vlastimil Burián Oct 20 '21 at 04:17
@LinuxSecurityFreak Okay, so actually restarting the machine made the disk re-appear under all circumstances... #classic. Everything seems to be up and running now. Thanks for your help and your efforts. – password is password Oct 20 '21 at 11:21
@LinuxSecurityFreak Oh and btw the Western Digital disk to be seen as /dev/sdb was another disk in the same machine. – password is password Oct 20 '21 at 11:23

Can't see mounted drive under lsblk, blkid or mount

1 Answers1

If not found there