Getting disk usage and folder usage Linux

Disk Usage

df (disk filesystem)  command will help us to know the disk usage in linux.  df command will display result in the following format

Filesystem           - List filesystem

1K-blocks             -  Total size of the file system

Used                      - used space

Available              - available space

Use%                     - percentage used.

Mounted on       - mounded as

df  command syntax is as follows

df  [options] [file]

The available options for df

Options	Description
-a, --all	include dummy file systems
-B, --block-size=SIZE	scale sizes by SIZE before printing them; e.g., '-BM' prints sizes in units of 1,048,576 bytes; see SIZE format below
--direct	show statistics for a file instead of mount point produce a grand total
--total
-h, --human-readable	print sizes in human readable format (e.g., 1K 234M 2G)
-H, --si	likewise, but use powers of 1000 not 1024
-i, --inodes	list inode information instead of block usage
-k	like --block-size=1K
-l, --local --no-sync       --output[=FIELD_LIST]	limit listing to local file systems do not invoke sync before getting usage info (default) use the output format defined by FIELD_LIST or print all fields if FIELD_LIST is omitted.
-P, --portability --sync	use the POSIX output format invoke sync before getting usage info
-t, --type=TYPE	limit listing to file systems of type TYPE
-T, --print-type	print file system type
-x, --exclude-type=TYPE	limit listing to file systems not of type TYPE
--version	version information
--help	display this help and exit

Folder usage

du Command display the amount of disk used by the specific files or directory.

This command helps us to know the disk usage for just directories/All files, showing grand total.

For example following command

$ du -sh /var

This will display  as the option given -s( display only total) h(human  readable format) the result is as follows

17G     /var

Options are follows

Options	Description
-0, --null	end each output line with 0 byte rather than newline
-a, --all --apparent-size	write counts for all files, not just directories print apparent sizes, rather than disk usage; although the apparent size is usually smaller, it may be larger due to holes in ('sparse') files, internal fragmentation, indirect blocks, and the like
-B, --block-size=SIZE	scale sizes by SIZE before printing them; e.g.,'-BM' prints sizes in units of 1,048,576 bytes; SIZE is an integer and optional unit (example: 10M is 10*1024*1024).  Units are K, M, G, T, P, E, Z, Y (powers of 1024) or KB, MB, ... (powers of 1000)
-b, --bytes	equivalent to '--apparent-size --block-size=1'
-c, --total	produce a grand total
-D, --dereference-args	dereference only symlinks that are listed on the command line
-d, --max-depth=N --files0-from=F	print the total for a directory (or file, with --all)  only if it is N or fewer levels below the command line argument;  --max-depth=0 is the same as –summarize summarize disk usage of the NUL-terminated file names specified in file F; if F is -, then read names from standard input
-H	equivalent to --dereference-args (-D)
-h, --human-readable --inodes	print sizes in human readable format (e.g., 1K 234M 2G) list inode usage information instead of block
-k	like --block-size=1K
-L, --dereference	dereference all symbolic links
-l, --count-links	count sizes many times if hard linked
-m	like --block-size=1M
-P, --no-dereference	don't follow any symbolic links (this is the default)
-S, --separate-dirs --si	for directories do not include size of subdirectories like -h, but use powers of 1000 not 1024
-s, --summarize	display only a total for each argument
-t, --threshold=SIZE --time --time=WORD --time-style=STYLE	exclude entries smaller than SIZE if positive, or entries greater than SIZE if negative show time of the last modification of any file in the directory, or any of its subdirectories show time as WORD instead of modification time: atime, access, use, ctime or status show times using STYLE, which can be: full-iso, long-iso, iso, or +FORMAT; FORMAT is interpreted like in 'date'
-X, --exclude-from=FILE --exclude=PATTERN	exclude files that match any pattern in FILE exclude files that match PATTERN
-x, --one-file-system	skip directories on different file systems
--help	display this help and exit
--version	output version information and exit