Master Linux mount and umount with 15 practical examples

After inserting a new hard disk, utilities like fdisk or parted create partitions, mkfs formats them (ext2/3/4), and mount attaches the filesystem to a directory.

1. Mount a CD-ROM

# mount -t iso9660 -o ro /dev/cdrom /mnt

The -o ro option mounts the CD read‑only; ensure the target directory /mnt exists.

2. View all mounted filesystems

# mount

Running mount without arguments lists every active mount, e.g., a USB drive appears as /dev/sdb on /media/myusb type vfat (rw, ...).

3. Mount everything listed in /etc/fstab

# mount -a

The -a flag reads /etc/fstab and mounts each entry that is not already active.

4. Mount a specific entry from /etc/fstab

# mount /mydata

If the directory name is supplied, mount searches /etc/fstab for a matching device and mounts it.

5. List mounts of a particular filesystem type

# mount -l -t ext2
# mount -l -t ext4

The -t option filters by type; the output shows the only ext2 and ext4 partitions on the system.

6. Mount a floppy disk

# mount /dev/fd0 /mnt
# cd /mnt

After mounting, the floppy’s contents are accessible; unmount with umount /mnt before removal.

7. Bind‑mount a directory

# mount -B /mydata /mnt

This creates an additional mount point /mnt that mirrors /mydata. Verification:

# mount | grep /mydata
# mount | grep /mnt

8. Move a mount point

# mount -M /mydata /mnt/

The -M option relocates the existing mount tree to a new location without unmounting.

9. Mount without updating /etc/mtab

# mount -n /dev/sda6 /mydata

The -n flag performs the mount but does not record it in /etc/mtab, so the mount is invisible to mount listings.

10. Mount read‑only or read/write

# mount /dev/sda6 /mydata -r
# mount -t ext4 -o ro -o noload /dev/sda6 /mydata

Use -r (or -o ro) for read‑only; add noload to prevent journal writes on ext3/4. Omit -r for the default read/write mode.

11. Remount an already mounted filesystem

# mount -o remount,rw /mydata

This changes a read‑only mount to read/write without unmounting.

12. Mount an ISO image

# mount -t iso9660 -o loop pdf_collections.iso /mnt

The -o loop option treats the ISO file as a block device.

13. Unmount multiple mount points at once

# umount /mydata /backup

14. Lazy unmount

# umount -l /mydata

The -l (lazy) flag detaches the filesystem immediately and completes the unmount after any pending I/O finishes.

15. Force unmount and troubleshoot busy mounts

# umount -f /mnt

If a device is busy, umount -f forces the unmount. To identify the holding process, use:

# ps ajx | grep /mydata
# fuser -cu /mydata

These commands show the PID and owner, allowing you to stop the process before retrying the unmount.