Chapter 16. Mounting file systems As a system administrator, you can mount file systems on your system to access data on them. 16.1. The Linux mount mechanism These are the basic concepts of mounting file systems on Linux. On Linux, UNIX, and similar operating systems, file systems on different partitions and removable devices (CDs, DVDs, or USB flash drives for example) can be attached to a certain point (the mount point) in the directory tree, and then detached again. While a file system is mounted on a directory, the original content of the directory is not accessible. Note that Linux does not prevent you from mounting a file system to a directory with a file system already attached to it. When mounting, you can identify the device by: a universally unique identifier (UUID): for example, UUID=34795a28-ca6d-4fd8-a347-73671d0c19cb a volume label: for example, LABEL=home a full path to a non-persistent block device: for example, /dev/sda3 When you mount a file system using the mount command without all required information, that is without the device name, the target directory, or the file system type, the mount utility reads the content of the /etc/fstab file to check if the given file system is listed there. The /etc/fstab file contains a list of device names and the directories in which the selected file systems are set to be mounted as well as the file system type and mount options. Therefore, when mounting a file system that is specified in /etc/fstab , the following command syntax is sufficient: Mounting by the mount point: Mounting by the block device: Additional resources mount(8) man page on your system How to list persistent naming attributes such as the UUID . 16.2. Listing currently mounted file systems List all currently mounted file systems on the command line by using the findmnt utility. Procedure To list all mounted file systems, use the findmnt utility: To limit the listed file systems only to a certain file system type, add the --types option: For example: Example 16.1. Listing only XFS file systems Additional resources findmnt(8) man page on your system 16.3. Mounting a file system with mount Mount a file system by using the mount utility. Prerequisites Verify that no file system is already mounted on your chosen mount point: Procedure To attach a certain file system, use the mount utility: Example 16.2. Mounting an XFS file system For example, to mount a local XFS file system identified by UUID: If mount cannot recognize the file system type automatically, specify it using the --types option: Example 16.3. Mounting an NFS file system For example, to mount a remote NFS file system: Additional resources mount(8) man page on your system 16.4. Moving a mount point Change the mount point of a mounted file system to a different directory by using the mount utility. Procedure To change the directory in which a file system is mounted: Example 16.4. Moving a home file system For example, to move the file system mounted in the /mnt/userdirs/ directory to the /home/ mount point: Verify that the file system has been moved as expected: Additional resources mount(8) man page on your system 16.5. Unmounting a file system with umount Unmount a file system by using the umount utility. Procedure Try unmounting the file system using either of the following commands: By mount point: By device: If the command fails with an error similar to the following, it means that the file system is in use because of a process is using resources on it: If the file system is in use, use the fuser utility to determine which processes are accessing it. For example: Afterwards, stop the processes using the file system and try unmounting it again. 16.6. Mounting and unmounting file systems in the web console To be able to use partitions on RHEL systems, you need to mount a file system on the partition as a device. Note You also can unmount a file system and the RHEL system will stop using it. Unmounting the file system enables you to delete, remove, or re-format devices. Prerequisites The cockpit-storaged package is installed on your system. You have installed the RHEL 8 web console. You have enabled the cockpit service. Your user account is allowed to log in to the web console. For instructions, see Installing and enabling the web console . If you want to unmount a file system, ensure that the system does not use any file, service, or application stored in the partition. Procedure Log in to the RHEL 8 web console. For details, see Logging in to the web console . Click the Storage tab. In the Storage table, select a volume from which you want to delete the partition. In the GPT partitions section, click the menu button, ... to the partition whose file system you want to mount or unmount. Click Mount or Unmount . 16.7. Common mount options The following table lists the most common options of the mount utility. You can apply these mount options using the following syntax: Table 16.1. Common mount options Option Description async Enables asynchronous input and output operations on the file system. auto Enables the file system to be mounted automatically using the mount -a command. defaults Provides an alias for the async,auto,dev,exec,nouser,rw,suid options. exec Allows the execution of binary files on the particular file system. loop Mounts an image as a loop device. noauto Default behavior disables the automatic mount of the file system using the mount -a command. noexec Disallows the execution of binary files on the particular file system. nouser Disallows an ordinary user (that is, other than root) to mount and unmount the file system. remount Remounts the file system in case it is already mounted. ro Mounts the file system for reading only. rw Mounts the file system for both reading and writing. user Allows an ordinary user (that is, other than root) to mount and unmount the file system.

Commands:
mount directory
mount device
findmnt
findmnt --types fs-type
findmnt --types xfs TARGET SOURCE FSTYPE OPTIONS / /dev/mapper/luks-5564ed00-6aac-4406-bfb4-c59bf5de48b5 xfs rw,relatime ├─/boot /dev/sda1 xfs rw,relatime └─/home /dev/mapper/luks-9d185660-7537-414d-b727-d92ea036051e xfs rw,relatime
findmnt mount-point
mount device mount-point
mount UUID=ea74bbec-536d-490c-b8d9-5b40bbd7545b /mnt/data
mount --types type device mount-point
mount --types nfs4 host:/remote-export /mnt/nfs
mount --move old-directory new-directory
mount --move /mnt/userdirs /home
findmnt ls old-directory ls new-directory
umount mount-point
umount device
umount: /run/media/user/FlashDrive : target is busy.
fuser --mount /run/media/user/FlashDrive /run/media/user/FlashDrive : 18351
mount --options option1,option2,option3 device mount-point