Daily Linux Command: Mount

mount is the command used in Linux systems to mount file systems. It allows you to connect devices (such as hard disk partitions, USB drives, CDs, etc.) or remote file systems to a specific directory in the file system, enabling access to their contents.

🔧 Basic Syntax

mount [options] [device] [mount point]

🧾 Common Examples

1. Mount a device to a specified directory

sudo mount /dev/sdb1 /mnt/usb

Note: Mounts the device /dev/sdb1 to the directory /mnt/usb.

Note: The mount point directory must exist beforehand.

2. View current mount information

mount

Or use:

df -h

Or:

findmnt

3. Mount a specified file system type (e.g., NTFS, vfat)

sudo mount -t ntfs /dev/sdb1 /mnt/usb

Common file system types include:

• ext4 (commonly used in Linux)
• ntfs (Windows partition)
• vfat (USB drives, FAT32)
• iso9660 (CD image)
• nfs (Network File System)

4. Mount using UUID (recommended method)

sudo mount UUID="1234-5678-90AB-CDEF" /mnt/data

You can check the UUID of a device using the following command:

blkid

5. Mount a read-only file system

sudo mount -o ro /dev/sdc1 /mnt/cdrom

6. Mount an ISO image file

sudo mount -o loop image.iso /mnt/iso

7. Unmount a file system

sudo umount /mnt/usb

Note: Ensure no programs are using the mount point before unmounting.

🛠️ Common Options (-o parameter)

Option	Description
ro	Read-only mount
rw	Read-write mount (default)
noauto	Do not automatically mount at startup
users	Allow ordinary users to mount/unmount
uid=1000	Set the user ID of files after mounting
gid=1000	Set the group ID of files after mounting
umask=0022	Set permission mask
loop	Mount image files (e.g., ISO)

📄 /etc/fstab file

Used to define file systems that are automatically mounted at system startup.

Example entry:

UUID=1234-5678-90AB-CDEF  /mnt/data  ext4  defaults  0  2

Field descriptions:

Field	Meaning
1	Device identifier (device path or UUID)
2	Mount point
3	File system type
4	Mount options (e.g., defaults)
5	Whether to be dumped (0/1)
6	File system check order (0-2)

📌 Tips

• When mounting USB drives or external hard drives, it is generally recommended to use directories under /media or /mnt as mount points.
• If you are using a desktop environment (like GNOME or KDE), devices are usually mounted automatically when inserted.
• If mounting fails, you can check the logs: dmesg or /var/log/syslog (depending on the distribution).