The command findmnt is used to find mounted filesystems in Linux. This command will look for a particular filesystem in /etc/fstab, /etc/mtab or /proc/self/mountinfo.
How to Install findmnt
The command findmnt comes in the package util-linux-ng, now renamed util-linux. The package comes with several other utilities such as hwclock. To install findmnt download util-linux from kernel.org ftp page.
How to Install findmnt in Fedora
Fedora users can install the package as follows:
$ sudo yum install util-linux-ng
Findmnt Default option
This command by default will give you a list of all filesystems mounted if no mountpoint or device is specified.
Findmnt Polling Mode
The command findmnt can be used to monitor changes in /proc/self/mountinfo file. The polling mode can be invoked by typing in your terminal the following command:
$ findmnt -p
$ findmnt --poll
Any changes made to /proc/self/mountinfo file will automatically be updated on the terminal. At first you will not see any output but if try unplug and plugging your flash drive, the changes are reflected on the terminal as in the following example.
The time which polling mode will block can be restricted by --timeout or --first-only option.
This option can be used along with --poll to limit the time polling mode will block to the time you explicitly set. The timeout to be set is in milliseconds. After the timeout period, findmnt will no longer monitor for changes to the /proc/self/mountinfo file.
$ findmnt --poll --timeout 6000
The first-only option will monitor for changes in the /proc/self/mountinfo file only for the first change and the command will no longer be in polling mode. The first change is displayed on the terminal and the prompt is returned to you. To use this option type on your terminal:
$ findmnt --poll --first-only
Imitating the command df output option
The command findmnt can also be used to imitate the output you would get if you used the df command. You can achieve this by running the command findmnt with the --df option as shown the following example.
$ findmnt --df
$ findmnt -D
This will give an almost identical output if you had run the command df with the -h option.
$ df -h
Findmnt list option
If you do not like the default tree output you can use the --list or -l option. This will print for you an output in a list format.
$ findmnt --list
Running this command will give you an output as follows:
Findmnt Evaluate Option
The evaluate option will convert all tags for example LABEL, UUID, PARTUUID or PARTLABEL to the actual device name. This option can be combined with --fstab option to print all the filesystems in /etc/fstab. The --fstab option has its output in list format, and therefore there is no need to call the --list option when --fstab is used.
$ findmnt --fstab --evaluate
When the two options are combined as follows, the output will look like the example below:
Findmnt type option
This option allows you to limit the set of printed filesystems. Multiple filesystems can be specified and separated by a coma. In this example the command will search for ext4, ext3 and vfat filesystems.
$ findmnt -t ext4,ext3,vfat
You can try out the different options for findmnt depending on your needs.