In the Linux world | Unix system administration One of our tasks is to perform disk space check in Linux. Performing a check disk space operation on Linux allows us to know about the current use of the mount point on the system. Here is a list of Linux commands for checking disk space.
Linux disk space check commands
1. The df command.
df is the main native command built inside Linux system used to check disk space on Linux. df stands for “free disk”. This means it displays the use of mount points in Linux. There are various options available for the df command. Without any options, it displays information like file system, used space, how much free space, and usage as a percentage, as shown below:
[[email protected] ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/mapper/vg_destroyer-lv_root 16070076 8763548 6490196 58% / tmpfs 1960684 36 1960648 1% /dev/shm /dev/sda1 495844 37181 433063 8% /boot /dev/mapper/vg_andreyex-lv_andreyex 198337 5647 182450 4% /andreyex /dev/sde1 1233308 3356 1167304 1% /home [[email protected] ~]#
There are various options within the df command, so let’s explore one by one.
and. Human readable format
The example output without any option displays the usage in bytes. In order to make it more informative, use the option “ -h “Along with the df command which will display usage in Gb. Mb as shown below:
[[email protected] ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_destroyer-lv_root 16G 8.4G 6.2G 58% / tmpfs 1.9G 36K 1.9G 1% /dev/shm /dev/sda1 485M 37M 423M 8% /boot /dev/mapper/vg_andreyex-lv_andreyex 194M 5.6M 179M 4% /andreyex /dev/sde1 1.2G 3.3M 1.2G 1% /home [[email protected] ~]#
b. Specific mount point
In “1a” the system displays information related to all mount points on the system. What if you want information related to a specific mount point. Then you must specify a mount point after the df command, which will print information about a specific mount point and only, for example, to display information related to / home, use the command point:
[[email protected] ~]# df -h /home Filesystem Size Used Avail Use% Mounted on /dev/sde1 1.2G 3.3M 1.2G 1% /home [[email protected] ~]#
from. Filesystem type
Let’s say you also need information related to the type of filesystem (ext2, ext3, or ext4) on the output. Use the “-T” option with the df command.
[[email protected] ~]# df -hT Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/vg_destroyer-lv_root ext4 16G 8.4G 6.2G 58% / tmpfs tmpfs 1.9G 36K 1.9G 1% /dev/shm /dev/sda1 ext4 485M 37M 423M 8% /boot /dev/mapper/vg_andreyex-lv_andreyex ext4 194M 5.6M 179M 4% /andreyex /dev/sde1 ext4 1.2G 3.3M 1.2G 1% /home [[email protected] ~]#
e. Limiting the list according to the type of file system
Including a certain type of file system.
In case you only want to (enable) the ext4 file system on the screen. Use “-t” followed by “filesystem type” as shown below:
[[email protected] ~]# df -hTt ext4 Filesystem Type Size Used Avail Use% Mounted on /dev/mapper/vg_destroyer-lv_root ext4 16G 8.4G 6.2G 58% / /dev/sda1 ext4 485M 37M 423M 8% /boot /dev/mapper/vg_andreyex-lv_andreyex ext4 194M 5.6M 179M 4% /andreyex /dev/sde1 ext4 1.2G 3.3M 1.2G 1% /home [[email protected] ~]#
Except for a certain type of file system type
Let’s say you don’t want the ext4 filesystem type to appear in the output, then you must use “-x” followed by the filesystem type.
[[email protected] ~]# df -hTx ext4 Filesystem Type Size Used Avail Use% Mounted on tmpfs tmpfs 1.9G 36K 1.9G 1% /dev/shm [[email protected] ~]#
In the output above, all ext4 file systems are excluded and only information for the “tmpfs” file system type is displayed.
e. Inode information.
If you want to print information related to the inode, then use the “-i” option with the df command.
[[email protected] ~]# df -hi Filesystem Inodes IUsed IFree IUse% Mounted on /dev/mapper/vg_destroyer-lv_root 999K 90K 909K 9% / tmpfs 479K 4 479K 1% /dev/shm /dev/sda1 126K 39 125K 1% /boot /dev/mapper/vg_andreyex-lv_andreyex 50K 12 50K 1% /andreyex /dev/sde1 77K 294 77K 1% /home [[email protected] ~]#
e. All file systems
In case you want to print information related to all file systems, which also includes a dummy file system. Then use the “-a” option after the df command as shown below:
[[email protected] ~]# df -ha Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_destroyer-lv_root 16G 8.4G 6.2G 58% / proc 0 0 0 - /proc sysfs 0 0 0 - /sys devpts 0 0 0 - /dev/pts tmpfs 1.9G 36K 1.9G 1% /dev/shm /dev/sda1 485M 37M 423M 8% /boot none 0 0 0 - /proc/sys/fs/binfmt_misc sunrpc 0 0 0 - /var/lib/nfs/rpc_pipefs /dev/mapper/vg_andreyex-lv_andreyex 194M 5.6M 179M 4% /andreyex /dev/sde1 1.2G 3.3M 1.2G 1% /home gvfs-fuse-daemon 0 0 0 - /root/.gvfs [[email protected] ~]#
2. The du command
The “du” command also shows the use of files or directories in Linux. du stands for “disk space usage”.
The basic command syntax is as follows:
du [options] [<file location> or <dir location>]
and. Readable
In order to display an image in a readable format, i.e. in terms of GB or MB, instead of the Kb variant, use “-h”.
[[email protected] tmp]# du -h 148K ./orbit-user1 4.0K ./ssh-LFeSg17790 4.0K ./mann 4.0K ./mannu 4.0K ./.esd-0 4.0K ./ssh-PYFhE19514 4.0K ./pulse-BIXXUmlVMfbC 4.0K ./.esd-513 4.0K ./.X11-unix 4.0K ./.ICE-unix 4.0K ./keyring-qO7Ako 4.0K ./pulse-WR3BqwGvaoeJ 84K ./orbit-user2 4.0K ./.esd-514 4.0K ./keyring-N0Gi7c 4.0K ./pulse-0lGpGWbHcush 12K ./orbit-root 492K . [[email protected] tmp]#
b. Specific file or directory
To display information related to any file or directory, use the du command as shown below:
For example, to use the tmp directory, use the command below.
[[email protected] tmp]# du -h /tmp 148K /tmp/orbit-user1 4.0K /tmp/ssh-LFeSg17790 4.0K /tmp/mann 4.0K /tmp/mannu 4.0K /tmp/.esd-0 4.0K /tmp/ssh-PYFhE19514 4.0K /tmp/pulse-BIXXUmlVMfbC 4.0K /tmp/.esd-513 4.0K /tmp/.X11-unix 4.0K /tmp/.ICE-unix 4.0K /tmp/keyring-qO7Ako 4.0K /tmp/pulse-WR3BqwGvaoeJ 84K /tmp/orbit-user2 4.0K /tmp/.esd-514 4.0K /tmp/keyring-N0Gi7c 4.0K /tmp/pulse-0lGpGWbHcush 12K /tmp/orbit-root 492K /tmp [[email protected] tmp]#
from. Simplify the output. You saw in output 2B that all files or directories were shown. However, if you do not want to show all directories, and instead you just want information related to that directory, then use with the “-c” option.
[[email protected] ~]# du -sh /tmp 492K /tmp [[email protected] ~]#
Please check the guidelines for extending the connection point if the usage threshold is reached.
