In this tutorial we will learn about, how to use df command to check the mounted filesystem on linux. As a Linux System administrator, this command is basic and very important.
The df command shows the usage of mounted filesystem.It is notable that the filesystems which are not mounted on system,we can not get its information by using df command.
We are writing some examples of df command which will help you in system administration.
Example 1: df command
Without using any other option with df command,it shows disk space in 1K blocks by default.
See the reference as given below :
Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda5 28835836 25781720 1589336 95% / udev 2025248 4 2025244 1% /dev tmpfs 814768 1052 813716 1% /run none 5120 4 5116 1% /run/lock none 2036912 3996 2032916 1% /run/shm none 102400 68 102332 1% /run/user cgroup 2036912 0 2036912 0% /sys/fs/cgroup /dev/sda7 9614116 3439440 5686304 38% /partition7 /dev/sda8 48062440 44482732 1138232 98% /partition8 /dev/sda9 76896316 53361192 19628924 74% /partition9 /dev/sda21 14418416 8003400 5682600 59% /partition10 root@tuxworld:~#
Example 2: Using -h option with df command
By using -h option with df command , print sizes in human readable format. Means it prints size in GB,MB etc.
Note: In first example,we have seen the sizes are in Kilobytes size.(By default)
See below given reference: In column Size,Used and Avail, you can see the sizes are in human readable format.
root@tuxworld:~# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda5 28G 25G 1.6G 95% / udev 2.0G 4.0K 2.0G 1% /dev tmpfs 796M 1.1M 795M 1% /run none 5.0M 4.0K 5.0M 1% /run/lock none 2.0G 4.0M 2.0G 1% /run/shm none 100M 68K 100M 1% /run/user cgroup 2.0G 0 2.0G 0% /sys/fs/cgroup /dev/sda7 9.2G 3.3G 5.5G 38% /partition7 /dev/sda8 46G 43G 1.1G 98% /partition8 /dev/sda9 74G 51G 19G 74% /partition9 /dev/sda21 14G 7.7G 5.5G 59% /partition10 root@tuxworld:~#
Example 3: Using -T option with df command
In this example we will use -T option with df command. Using -T options print the type of filesystem. For example, the filesystem type can be ext2,ext3,ext4,tmpfs etc. This information sometimes very helpful for Linux System Administrator,in terms of troubleshooting and auditing.
See below given reference: Here we will use -T option with df command. To make the output more user friendly we will also use -h option.
In below given output, you can see Type column which is shown after using -T option.
root@tuxworld:~# df -Th Filesystem Type Size Used Avail Use% Mounted on /dev/sda5 ext4 28G 25G 1.6G 95% / udev devtmpfs 2.0G 4.0K 2.0G 1% /dev tmpfs tmpfs 796M 1.1M 795M 1% /run none tmpfs 5.0M 4.0K 5.0M 1% /run/lock none tmpfs 2.0G 4.0M 2.0G 1% /run/shm none tmpfs 100M 68K 100M 1% /run/user cgroup tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup /dev/sda7 ext4 9.2G 3.3G 5.5G 38% /partition7 /dev/sda8 ext3 46G 43G 1.1G 98% /partition8 /dev/sda9 ext3 74G 51G 19G 74% /partition9 /dev/sda21 ext4 14G 7.7G 5.5G 59% /partition10 root@tuxworld:~#
Example 4: Using -i option with df command
By using -i option along with df command ,print the inode information of filesystem.
As per my experience, I have seen the cases when inode become 100% in use. Whereas using df -h shown me some free space was available.
Note: Because of Inode use (IUse%) is 100%, many application stops working. Always remember this option for troubleshooting purpose.
See below given reference:
root@tuxworld:~# df -ih Filesystem Inodes IUsed IFree IUse% Mounted on /dev/sda5 1.8M 777K 1012K 44% / udev 202K 696 201K 1% /dev tmpfs 208K 733 207K 1% /run none 208K 5 208K 1% /run/lock none 208K 21 208K 1% /run/shm none 208K 29 207K 1% /run/user cgroup 208K 9 208K 1% /sys/fs/cgroup /dev/sda7 597K 828 596K 1% /partition7 /dev/sda8 3.0M 13K 3.0M 1% /partition8 /dev/sda9 4.7M 11K 4.7M 1% /partition9 /dev/sda21 895K 221K 674K 25% /partition10 root@tuxworld:~#
Example 5: Using -t option with df command
When we use -t option with df command, we have to also define the type of filesystem we want to print on screen. Here, type of filesystem meaning is ext2,ext3,ext4,tmpfs,sysfs etc.
To understand -t option, I will show 2 sample references.
Reference 1: In this reference,I have used only -t option and want to print ext4 filesystem which are mounted.
root@tuxworld:~# df -t ext4 Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda5 28835836 25781868 1589188 95% / /dev/sda7 9614116 3439440 5686304 38% /partition7 /dev/sda21 14418416 8003400 5682600 59% /partition10 root@tuxworld:~#
Reference 2: The command is same as we have seen in Reference 1. To make the output more user friendly we will use -h and -T .(Read above examples, to understand -h and -T options)
root@tuxworld:~# df -t ext4 -Th Filesystem Type Size Used Avail Use% Mounted on /dev/sda5 ext4 28G 25G 1.6G 95% / /dev/sda7 ext4 9.2G 3.3G 5.5G 38% /partition7 /dev/sda21 ext4 14G 7.7G 5.5G 59% /partition10 root@tuxworld:~#
Example 6: Show all mounted filesystem including dummy filesystem
Using -a option with df command, prints all filesystems including dummy filesystem. Hence, by using -a option you can know what are the dummy filesystems are available in your system .
You can also use other options along with -a .
root@tuxworld:~# df -a Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda5 28835836 25781876 1589180 95% / proc 0 0 0 - /proc sysfs 0 0 0 - /sys none 0 0 0 - /sys/fs/fuse/connections none 0 0 0 - /sys/kernel/debug none 0 0 0 - /sys/kernel/security udev 2025248 4 2025244 1% /dev devpts 0 0 0 - /dev/pts tmpfs 814768 1052 813716 1% /run none 5120 4 5116 1% /run/lock none 2036912 3996 2032916 1% /run/shm none 102400 68 102332 1% /run/user cgroup 2036912 0 2036912 0% /sys/fs/cgroup cgroup 0 0 0 - /sys/fs/cgroup/cpuset cgroup 0 0 0 - /sys/fs/cgroup/cpu cgroup 0 0 0 - /sys/fs/cgroup/cpuacct cgroup 0 0 0 - /sys/fs/cgroup/memory cgroup 0 0 0 - /sys/fs/cgroup/devices cgroup 0 0 0 - /sys/fs/cgroup/freezer cgroup 0 0 0 - /sys/fs/cgroup/blkio cgroup 0 0 0 - /sys/fs/cgroup/perf_event /dev/sda7 9614116 3439440 5686304 38% /partition7 /dev/sda8 48062440 44482732 1138232 98% /partition8 /dev/sda9 76896316 53361192 19628924 74% /partition9 /dev/sda21 14418416 8003400 5682600 59% /partition10 binfmt_misc 0 0 0 - /proc/sys/fs/binfmt_misc gvfsd-fuse 0 0 0 - /run/user/linux/gvfs root@tuxworld:~#
