**Filesystem Size Used Avail Use% Mounted on**
/dev/sdc 339G -21G 342G - /mnt/HC_Volume_5017960
/dev/sdd 663G 27G 603G 5% /mnt/volume-nbg1-2
A new volume was added to hosting provided by https://hetzner.com located in /mnt/HC_Volume_5017960
When copying using dd, an incomprehensible error occurred (the process was interrupted) and the volume size became incorrect. I created a new directory in mnt and mounted the disk, now the disk size shows correctly, but now it is named /dev/sdd. How to delete a section /dev/sdс? it is impossible to unmount and read the section,restart the server I also can not.
# umount /dev/sdc
-bash: /bin/umount: cannot execute binary file: Exec format error
/mnt/HC_Volume_5017960 # ls
ls: reading directory '.': Input/output error
cat /proc/mounts
/dev/sdc /mnt/HC_Volume_5017960 ext4 ro,relatime,discard,data=ordered 0 0
/dev/sdd /mnt/volume-nbg1-2 ext4 rw,relatime,discard,data=ordered 0 0
cat /etc/fstab
/dev/disk/by-id/scsi-0HC_Volume_5017960 /mnt/HC_Volume_5017960 ext4 discard,nofail,defaults 0 0
/dev/disk/by-id/scsi-0HC_Volume_5017960 /mnt/volume-nbg1-2 ext4 discard,nofail,defaults 0 0