Linux list mounted disks

Is there a command to see where a disk is mounted?

Is there a simple command that takes a disk’s device node as input, and tells me where (and whether) that disk is mounted? Is it possible to get the mount point by itself, so I can pass it to another command? I’m working on a Debian Squeeze live system with a minimal install (I can install extra packages if need be).

6 Answers 6

On Linux, you can now use the findmnt command from util-linux (since version 2.18):

$ findmnt -S /dev/VG_SC/home TARGET SOURCE FSTYPE OPTIONS /home /dev/mapper/VG_SC-home ext4 rw,relatime,errors=remount-ro,data=ordered 

Or lsblk (also from util-linux , since 2.19):

$ lsblk /dev/VG_SC/home NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT VG_SC-home 254:2 0 200G 0 lvm /home 

That one is also useful to find all the file system mounted under a specific device (disk or partition. ):

$ lsblk /dev/sda2 NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda2 8:2 0 59.5G 0 part ├─linux-debian64 (dm-1) 252:1 0 15G 0 lvm └─linux-mint (dm-2) 252:2 0 15G 0 lvm / 

To get the mountpoint only:

$ findmnt -nr -o target -S /dev/storage/home /home $ lsblk -o MOUNTPOINT -nr /dev/storage/home /home 

Above findmnt does return with a failure exit status if the device is not mounted, not lsblk .

if mountpoint=$(findmnt -nr -o target -S "$device"); then printf '"%s" is mounted on "%s"\n' "$device" "$mountpoint" else printf '"%s" does not appear to be directly mounted\n' "$device" fi 

Under Linux, you can get mount point information directly from the kernel in /proc/mounts . The mount program records similar information in /etc/mtab . The paths and options may be different, as /etc/mtab represents what mount passed to the kernel whereas /proc/mounts shows the data as seen inside the kernel. /proc/mounts is always up-to-date whereas /etc/mtab might not be if /etc was read-only at some point that wasn’t expected by the boot scripts. The format is similar to /etc/fstab .

In both files, the first whitespace-separated field contains the device path and the second field contains the mount point.

awk -v needle="$device_path" '$1==needle ' /proc/mounts 

grep "^$device_path " /proc/mounts | cut -d ' ' -f 2 

There are a number of edge cases where you might not get what you expect. If the device was mounted via a different path in /dev that designates the same device, you won’t notice it this way. In /proc/mounts , bind mounts are indistinguishable from the original. There may be more than one match if a mount point shadows another (this is unusual).

In /proc/self or /proc/$pid , there is a per-process mounts file that mimics the global file. The mount information may vary between processes, for example due to chroot . There is an additional file called mountinfo that has a different format and includes more information, in particular the device major and minor numbers. From the documentation:

36 35 98:0 /mnt1 /mnt2 rw,noatime master:1 - ext3 /dev/root rw,errors=continue (1)(2)(3) (4) (5) (6) (7) (8) (9) (10) (11) (1) mount ID: unique identifier of the mount (may be reused after umount) (2) parent ID: ID of parent (or of self for the top of the mount tree) (3) major:minor: value of st_dev for files on filesystem (4) root: root of the mount within the filesystem (5) mount point: mount point relative to the process's root (6) mount options: per mount options (7) optional fields: zero or more fields of the form "tag[:value]" (8) separator: marks the end of the optional fields (9) filesystem type: name of filesystem of the form "type[.subtype]" (10) mount source: filesystem specific information or "none" (11) super options: per super block options 

So if you’re looking for a device by number, you can do it like this:

awk -v dev="$major:minor" '$3==dev ' awk -v dev="$(stat -L -c %t:%T /dev/block/something)" '$3==dev ' 

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How do I see all mounts in Linux?

I was asked how to see all mount points in Linux. Even though I always did it for myself using the mount command, I was surprised when I found there was no more human-friendly way I could explain. Thus I decided to write a tutorial that includes different techniques to achieve it.

While running commands to get mount points information is pretty easy, dealing with the output may not be comfortable for some users. After reading this tutorial, you’ll know how to get different outputs through different available commands: cat, findmnt, mount and df. Yet no format is really human friendly.

See mount points using findmnt:

The command findmnt lists all mount points. To do this the findmnt reads files /etc/fstab, /etc/fstab.d, /etc/mtab or /proc/self/mountinfo.

To run it, simply just the command below.

As you can see in the output, there are 4 columns:

• TARGET: This column shows the mount point.
• SOURCE: In this column, you can see the mounted device.
• FSTYPE: Here is described the file system.
• OPTIONS: This column shows mount point options, such as Read-Only or Writable.

You can get additional information on findmnt at https://linux.die.net/man/8/findmnt.

Show mount points using cat:

The most accurate technique to see mount points in Linux is reading the /proc/mounts file using cat. This is also the less human-friendly way, with the worse visual output.

The advantage of this method is that the kernel directly provides the information to see mount points over more human-friendly ways as alternatives explained in this tutorial

To see all mount points using cat, run the command as shown below.

As you can see, the output isn’t user friendly, but it is considered the most accurate method to check mounted devices in Linux.

See mount points using the mount command:

The mount is probably the most known command explained in this tutorial. Once we needed to run it every time we wanted to mount a device, it wasn’t automatic like today. By running it, you’ll get an output with all mounted filesystems. If followed by the -l flag, it will also show the mount point name; the output is similar to the mount command without flags.

As you can see, in the last two lines, there is a mounted pen drive containing a Kali Linux distribution.

Show mount points using df (Disk Free):

The df (Disk Free) command is also useful to print all mount points. The df command is mainly used to show available and used space on all storage devices.

To get an output with all mount points using df, just run it without additional options, as shown below.

Again you can see in the last line the /dev/sdb1 storage device is mounted.

This output displays 4 columns:

• Filesystem: This column shows the filesystem.
• 1K-Blocks: Here, you can see the size.
• Used: This column shows used space (in 1K blocks).
• Available: Available used space (in 1K blocks).
• Use%: Percentage of used space
• Mounted on: Mount point.

You can get more information on df at Linux Commands for Disk Space.

What happens when we mount or unmount a device in Linux?

When you mount a filesystem, like a cd, or a hard disk or USB stick, you create a mount point within your system. This mount point means virtually storing the cd, hard disk or USB stick’s content within your system. The files are not really stored in your system’s storage, but the system makes them accessible from itself by importing them under its filesystem hierarchy.

When you unmount a device, do exactly the opposite and instruct the system to stop providing mount points for external files.

Today mounting devices isn’t a common task since more user-friendly Linux distributions took over the market. Once, users needed to mount every external device manually, specifying the external device path and filesystem.

Conclusion:

As you can see, seeing all mounts in Linux is pretty easy. Linux offers you a variety of techniques to achieve this task by just running a command. As highlighted in the tutorial, the cat method is the most accurate and less human-friendly.

Other tools like findmnt feature a little improvement in the format, making it more user-friendly. Mounting, unmounting, and checking mount points status is a basic knowledge any Linux user-level must hold. Some Unix-like Linux distributions like Slackware don’t include automount enabled by default.

Thank you for reading this tutorial explaining how to see all mounts in Linux. Keep following Linux Hint for more Linux tips and tutorials.

About the author

David Adams

David Adams is a System Admin and writer that is focused on open source technologies, security software, and computer systems.

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4 Commands to List Mounted File Systems in Linux

The Linux operating system provides multiple filesystems, including ext4, xfs, tmpfs, securityfs, and many more. This guide demonstrates various ways to list all mounted file systems in a Linux system.

1. View Linux Mounted Filesystem Using /proc Filesystem

The /proc/mounts file is a file that displays the status of all filesystems that are currently mounted on the system. The file format closely resembles that of the /etc/fstab file. The file reports the status of mounted filesystems as recorded by the Linux kernel.

Thus, to view all the mounted filesystems, view the /proc/mounts file using the cat command as shown.

2. List Linux Mounted Filesystem Using df Command

The df command is mostly used to check disk space utilization on mounted file systems. It lists, among other statistics, total disk space and available disk space on each mounted filesystem.

When the -a option is included, the df command lists all the mounted filesystems.

3. Print Linux Mounted Filesystems Using findmnt Command

The findmnt command is yet another powerful command that displays all mounted filesystems on your Linux system in a tree-like format.

To print all the mounted filesystems, simply run the command without any arguments.

This prints the output in a tree-like format as shown.

You can pass the -D option which will print the output similar to the df -Th command

Pass the -t option followed by the filesystem type to print specific filesystems. For example, to view all the mounted EXT4 filesystems, run the command:

To view all EXT4 filesystems mounted in the /etc/fstab file, run the command:

4. Show Mounted Linux Filesystem Using mount Command

You can also use the mount command to list all mounted file systems. Without any arguments, it lists all the mounted filesystems.

Summing Up

In this guide, we have explored four ways that you can use to list all mounted file systems in a Linux system. Your views and feedback on this guide are welcome.

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How do I check where devices are mounted?

What is the command that lets me see what and where devices are mounted? I’m having trouble changing songs on my old iPod, and I have a feeling it’s because of the mount point.

3 Answers 3

There are at least three programs I know of that list device mount points:

mount — mount a filesystem (used for general mount info too):

$ mount /dev/sda3 on / type ext4 (rw,errors=remount-ro) proc on /proc type proc (rw,noexec,nosuid,nodev) sysfs on /sys type sysfs (rw,noexec,nosuid,nodev) . /dev/mapper/lvmg-homelvm on /home type btrfs (rw,relatime,compress=lzo,space_cache) /dev/sda5 on /home/muru/arch type btrfs (rw,relatime,compress=lzo,space_cache) binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev) systemd on /sys/fs/cgroup/systemd type cgroup (rw,noexec,nosuid,nodev,none,name=systemd) 

$ df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda3 30832636 11993480 17249912 42% / none 4 0 4 0% /sys/fs/cgroup . /dev/sda5 31457280 3948600 25396496 14% /home/bro3886/arch 

$ lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 465.8G 0 disk ├─sda1 8:1 0 100M 0 part ├─sda2 8:2 0 58.5G 0 part ├─sda3 8:3 0 30G 0 part / ├─sda4 8:4 0 1K 0 part ├─sda5 8:5 0 30G 0 part ├─sda6 8:6 0 339.2G 0 part │ └─lvmg-homelvm (dm-0) 252:0 0 1.2T 0 lvm └─sda7 8:7 0 8G 0 part [SWAP] sdb 8:16 0 931.5G 0 disk └─sdb1 8:17 0 931.5G 0 part └─lvmg-homelvm (dm-0) 252:0 0 1.2T 0 lvm 

Of these three, mount lists all the mountpoints, AFAICT. The others have their weaknesses.

findmnt suggested by @webwurst is now my favourite tool for the job. It’s a Swiss Army knife when it comes to output control (newer versions can output in JSON too):

$ findmnt / TARGET SOURCE FSTYPE OPTIONS / /dev/sda1 ext4 rw,relatime,errors=remount-ro,data=ordered $ findmnt / -no source /dev/sda1 $ findmnt / --json < "filesystems": [ ] > $ findmnt / --df SOURCE FSTYPE SIZE USED AVAIL USE% TARGET /dev/sda1 ext4 40.2G 25.8G 12.5G 64% / 

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