dmesg - print or control the kernel ring buffer
dmesg is used to examine or control the kernel ring buffer.
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lsblk
Utility which displays a nice tree view of the storage volumes (since util-linux 2.19, not present on embedded devices with BusyBox).
umount – unmount file systems
Examples
umount /mnt/md0
umount /home
Repair Instruction
e2fsck -p /dev/mapper/vg0-lv0
btrfs Check structural integrity of a filesystem (unmounted).
umount svbbtrfs check /dev/mapper/vg4-lv4 –force
fsck -nf /dev/sda1
If you just use fsck to check the volume you can run
- n -> dry-run: will not do any change (just checking)
- f -> force : sometimes it says
cleanbut you can force a new check
If you want to fix filesystem errors, first unmount your partition: umount /dev/sda1
umount /dev