mount command

mount - mount a filesystem

Usage: mount [options] [device] [mount_point]

• device: The filesystem to mount (e.g., /dev/sdb1, an ISO file).
• mount_point: The directory where the filesystem will be accessible (e.g., /mnt).
• options: Flags to modify behavior or specify mount settings.

Common Options

Option	Description
-t	Specify filesystem type
-o	Set mount options
-a	Mount all filesystems in /etc/fstab
-r	Mount read-only (same as -o ro)
-w	Mount read-write (same as -o rw)
-o loop	Mount a file as a loop device

Examples

• Listing Mounted Filesystems

  Run mount without arguments to see all currently mounted filesystems.

  mount
  • Output (partial):

    /dev/sda1 on / type ext4 (rw,relatime)
    /dev/sdb1 on /mnt/data type ntfs (rw,nosuid,nodev)
  • Explanation:
    • /dev/sda1: Device.
    • /: Mount point.
    • ext4: Filesystem type.
    • (rw,relatime): Mount options (read-write, relative time).

• Mounting a Device

  Mount a device to a directory (create the directory first if needed).

  sudo mkdir /mnt/usb
  sudo mount /dev/sdb1 /mnt/usb
  • Mounts the partition /dev/sdb1 (e.g., a USB drive) to /mnt/usb.
  • Access files with ls /mnt/usb.

  Check:

  mount | grep /mnt/usb
  • Confirms it’s mounted.

• Specifying Filesystem Type

  Use -t to specify the filesystem type if it’s not auto-detected.

  sudo mount -t ntfs /dev/sdb1 /mnt/usb
  • Mounts /dev/sdb1 as an NTFS filesystem.

  Common types: ext4, ntfs, vfat (FAT32), iso9660 (CD/DVD).

• Mounting with Options

  Use -o to set mount options (e.g., read-only, user permissions).

  Example (Read-Only):

  sudo mount -o ro /dev/sdb1 /mnt/usb
  • Mounts as read-only (ro).

  Example (User Access):

  sudo mount -o uid=1000,gid=1000 /dev/sdb1 /mnt/usb
  • Allows a specific user (UID 1000) to access it.

  Common options:

  • rw: Read-write.
  • ro: Read-only.
  • nosuid: Block setuid binaries.
  • remount: Change options on an existing mount.

• Mounting an ISO File

  Mount an ISO image as a loop device.

  sudo mkdir /mnt/iso
  sudo mount -o loop diskimage.iso /mnt/iso
  • Mounts diskimage.iso to /mnt/iso.
  • Access contents with ls /mnt/iso.

• Automatic Mounting with /etc/fstab

  Edit /etc/fstab for persistent mounts at boot.

  Add to /etc/fstab:

  /dev/sdb1  /mnt/usb  ext4  defaults  0  2
  • Then test or apply:

    sudo mount -a
  • Mounts all fstab entries.

• Remounting

  Use -o remount to change options without unmounting.

  sudo mount -o remount,ro /mnt/usb
  • Changes /mnt/usb to read-only.

To get help related to the mount command use --help option

$ mount --help

Usage:
 mount [-lhV]
 mount -a [options]
 mount [options] [--source] <source> | [--target] <directory>
 mount [options] <source> <directory>
 mount <operation> <mountpoint> [<target>]

Mount a filesystem.

Options:
 -a, --all               mount all filesystems mentioned in fstab
 -c, --no-canonicalize   don't canonicalize paths
 -f, --fake              dry run; skip the mount(2) syscall
 -F, --fork              fork off for each device (use with -a)
 -T, --fstab <path>      alternative file to /etc/fstab
 -i, --internal-only     don't call the mount.<type> helpers
 -l, --show-labels       show also filesystem labels
 -n, --no-mtab           don't write to /etc/mtab
     --options-mode <mode>
                         what to do with options loaded from fstab
     --options-source <source>
                         mount options source
     --options-source-force
                         force use of options from fstab/mtab
 -o, --options <list>    comma-separated list of mount options
 -O, --test-opts <list>  limit the set of filesystems (use with -a)
 -r, --read-only         mount the filesystem read-only (same as -o ro)
 -t, --types <list>      limit the set of filesystem types
     --source <src>      explicitly specifies source (path, label, uuid)
     --target <target>   explicitly specifies mountpoint
     --target-prefix <path>
                         specifies path used for all mountpoints
 -v, --verbose           say what is being done
 -w, --rw, --read-write  mount the filesystem read-write (default)
 -N, --namespace <ns>    perform mount in another namespace

 -h, --help              display this help
 -V, --version           display version

Source:
 -L, --label <label>     synonym for LABEL=<label>
 -U, --uuid <uuid>       synonym for UUID=<uuid>
 LABEL=<label>           specifies device by filesystem label
 UUID=<uuid>             specifies device by filesystem UUID
 PARTLABEL=<label>       specifies device by partition label
 PARTUUID=<uuid>         specifies device by partition UUID
 ID=<id>                 specifies device by udev hardware ID
 <device>                specifies device by path
 <directory>             mountpoint for bind mounts (see --bind/rbind)
 <file>                  regular file for loopdev setup

Operations:
 -B, --bind              mount a subtree somewhere else (same as -o bind)
 -M, --move              move a subtree to some other place
 -R, --rbind             mount a subtree and all submounts somewhere else
 --make-shared           mark a subtree as shared
 --make-slave            mark a subtree as slave
 --make-private          mark a subtree as private
 --make-unbindable       mark a subtree as unbindable
 --make-rshared          recursively mark a whole subtree as shared
 --make-rslave           recursively mark a whole subtree as slave
 --make-rprivate         recursively mark a whole subtree as private
 --make-runbindable      recursively mark a whole subtree as unbindable

For more details, check the manual with man mount