In the world of Linux systems administration, monitoring and managing disk space is a critical task. The df command is a powerful tool that provides essential information about disk usage on Linux systems. On the internet, you will find plenty of tools for checking disk space utilization in Linux.
The df command stands for “disk free” and is used to display information about available and used disk space on Linux systems. It provides a summary of filesystem usage, including the total size, used space, available space, and the mount point of each filesystem.
Using ‘-h‘ parameter with (df -h) will show the file system disk space statistics in “human-readable” format, which means it gives the details in bytes, megabytes, and gigabytes. In this article, we will explore the df command in depth, discussing its usage, options, and practical examples.
1. Check File System Disk Space Usage
The “df” command displays the information of device name, total blocks, total disk space, used disk space, available disk space, and mount points on a file system.
df
Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on
/dev/disk1s1s1 976490576 17725680 559478496 4% 356093 2797392480 0% /
devfs 377 377 0 100% 652 0 100% /dev
/dev/disk1s3 976490576 4322480 559478496 1% 2268 2797392480 0% /System/Volumes/Preboot
/dev/disk1s5 976490576 4194360 559478496 1% 2 2797392480 0% /System/Volumes/VM
/dev/disk1s6 976490576 21904 559478496 1% 16 2797392480 0% /System/Volumes/Update
/dev/disk1s2 976490576 388192304 559478496 41% 2066872 2797392480 0% /System/Volumes/Data
map auto_home 0 0 0 100% 0 0 100% 2. Display Information on all File System Disk Space Usage
The same as above, but it also displays information on dummy file systems along with all the file system disk usage and their memory utilization.
df -a
Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on
/dev/disk1s1s1 976490576 17725680 559494152 4% 356093 2797470760 0% /
devfs 377 377 0 100% 652 0 100% /dev
/dev/disk1s3 976490576 4322480 559494152 1% 2268 2797470760 0% /System/Volumes/Preboot
/dev/disk1s5 976490576 4194360 559494152 1% 2 2797470760 0% /System/Volumes/VM
/dev/disk1s6 976490576 21904 559494152 1% 16 2797470760 0% /System/Volumes/Update
/dev/disk1s2 976490576 388176648 559494152 41% 2066964 2797470760 0% /System/Volumes/Data
map auto_home 0 0 0 100% 0 0 100% /System/Volumes/Data/home3. Show Disk Space Usage in Human Readable Format
-h or --human-readable: Displays the output in a human-readable format, using units like kilobytes (K), megabytes (M), and gigabytes (G).
df -h
Filesystem Size Used Avail Capacity iused ifree %iused Mounted on
/dev/disk1s1s1 466Gi 8.5Gi 267Gi 4% 356093 2797384680 0% /
devfs 189Ki 189Ki 0Bi 100% 652 0 100% /dev
/dev/disk1s3 466Gi 2.1Gi 267Gi 1% 2268 2797384680 0% /System/Volumes/Preboot
/dev/disk1s5 466Gi 2.0Gi 267Gi 1% 2 2797384680 0% /System/Volumes/VM
/dev/disk1s6 466Gi 11Mi 267Gi 1% 16 2797384680 0% /System/Volumes/Update
/dev/disk1s2 466Gi 185Gi 267Gi 41% 2067166 2797384680 0% /System/Volumes/Data
map auto_home 0Bi 0Bi 0Bi 100% 0 0 100% /System/Volumes/Data/home4. Display Information of File System in Bytes
To display all file system information and usage in 1024-byte blocks, use the option ‘-k‘ (e.g. --block-size=1K) as follows.
df -k
Filesystem 1024-blocks Used Available Capacity iused ifree %iused Mounted on
/dev/disk1s1s1 488245288 8862840 279741428 4% 356093 2797414280 0% /
devfs 188 188 0 100% 652 0 100% /dev
/dev/disk1s3 488245288 2161244 279741428 1% 2268 2797414280 0% /System/Volumes/Preboot
/dev/disk1s5 488245288 2097180 279741428 1% 2 2797414280 0% /System/Volumes/VM5. Display Information of File System in MB
To display information on all file system usage in MB (MegaByte) use the option ‘-m‘.
df -m
Filesystem 1M-blocks Used Available Capacity iused ifree %iused Mounted on
/dev/disk1s1s1 476802 8655 273178 4% 356093 2797345920 0% /
devfs 0 0 0 100% 652 0 100% /dev6. Display File System Inodes
Using ‘-i‘ switch will display the information of a number of used inodes and their percentage for the file system.
df -i
Filesystem 512-blocks Used Available Capacity iused ifree %iused Mounted on
/dev/disk1s1s1 976490576 17725680 559468272 4% 356093 2797341360 0% /
devfs 377 377 0 100% 652 0 100% /dev