Mount and Unmount


After the file system is set up, devices cannot be used until mounted.

Windows and macOS can mount automatically.

Linux without desktop environment or other services will not mount on their own.

It is advised to use /mnt directory. But there is no restrictions.

Some disks should be mounted at / Some details about root mount (see highest voted answer)



mount                # display mount information
mount /dev/sda3 /mnt # device-to-mount point-to-mount

(Read man page for more details)


  • Specify the file system type
  • When failed to recognize automatically

-o [options]

  • remount
    • re mount
    • must remount if wish to change the mount options
  • ro/rw
    • read only
    • read write (default)
  • sync
    • disable cache, all operations are written directly to disk
      • Linux usually write changes into cache (in memory) and write to disks when the system is idle
    • may be safer but slower
    • only necessary when the power is very unstable and the data are very important
  • async
    • enable cache (default)
  • noatime
    • do not update the access time of accessed files
    • improve efficacy especially with high disk operations frequency
  • atime
    • access time
    • update access time (default)
  • Use commas (,) to separate different flags in one command


umount <some-device>
umount <some-mount-points>

un mount

Must unmount before any operations on file systems.

Handle Busy Device


fuser -m <some-mount-point>

file user

Check which process is using given mount point


lsof <some-path>

list open file

list the files that are being used

Auto Mount at Boot


file systems table file

Lines begin with # are comments

Each line (in 5 parts) represents a auto-mount config:

  1. The device to mount
    • e.g. /dev/sda3
    • LABEL=XXX can be used to replace /dev/sda3
    • UUID can also be used
  2. The mount point
  3. File system
  4. Mount Options (see above)
    • e.g. defaults
  5. Options for dump and fsck
    • e.g. 0 0
    • Usually no need to change

Use Tab to format

mount -a can be used to mount fstab