fsck & xfs_repair → filesystem check

• fsck → ext2, ext3, ext4

• xfs_repair → xfs only

• Made each boot & fix it

• df -T → check

  • Unmount before fsck

fsck error code

• 0 → no error

• 1 → error corrected

• 2 → reboot needed

• 4 → some error left uncorrected

• 8 → operational error

• -f → force

• -y → repair automatically

• fsck /dev/sdb

• umount /bigdata

• xfs_repair /dev/mapper/stratis...

dd → disk cloning

• dd if=<sourcefilename> of=<targetfilename>

• dd if=/dev/sda1 of=/root/sda1.img

  • Backup copy disk partition

• dd if=/root/sda1.img of=/dev/sdb3

  • Restore