du command works well, disk space is well known

As a public environment, the server development environment often encounters disk space bursts (I don't know if you've ever encountered this, but I often do). Since many of our development classmates put files on it, in this case we can only delete our useless files first. However, I have encountered a situation before, I deleted the 10 G files previously stored, free up less than two minutes, disk space is full again!!!

So it's very important to know the command of viewing server disk space. Otherwise, how can you find out what is causing the disk space to grow so fast? Let's go on and see how to use the command du accurately so that we can make fewer detours in normal development.

Say, the following commands are all the results of root user execution in centos7.6 environment.

du

Displays a summary of disk usage for the catalog

[root@hadoop3 /]# du /tmp
4       /tmp/.font-unix
4       /tmp/.ICE-unix
4       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4       /tmp/.XIM-unix
260     /tmp/hsperfdata_root
4       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4       /tmp/.Test-unix
4       /tmp/.X11-unix
300     /tmp

Command Details: The'du'command without any options lists all files and folders in a given directory or current working directory. In addition, it will display as a block along their path, and at the bottom of the page, it will display the total file size as a block. As you can see in the example above, the file path is displayed with the block size of an existing file. However, the output above is not in a readable format, which is its main disadvantage.

du -h

Display a summary of disk usage for the catalog as readable

[root@hadoop3 /]# du -h /tmp
4.0K    /tmp/.font-unix
4.0K    /tmp/.ICE-unix
4.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4.0K    /tmp/.XIM-unix
260K    /tmp/hsperfdata_root
4.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4.0K    /tmp/.Test-unix
4.0K    /tmp/.X11-unix
300K    /tmp

Command Details: Using the'du-h'option will list all outputs in a'readable format'. This'-h'option converts the block size to a readable format, such as Bytes, Kilobytes, Megabytes, or Gigabytes. In the example above, you can see that all file sizes are printed as output K.

du -sh

View total disk usage for a specific directory

[root@hadoop3 /]# du -sh /tmp
300K    /tmp

Command details:'du-sh'option will show the exact size of the directory used.'- The s'flag will show the total number of directories with block sizes, but a combination of the'-h' flags will convert the output to a readable format. This command is used most frequently in practice.

du -a

List disk usage for all files/subfiles in this directory

[root@hadoop3 /]# du -a /tmp
4       /tmp/.font-unix
4       /tmp/.ICE-unix
4       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4       /tmp/.XIM-unix
32      /tmp/hsperfdata_root/5057
32      /tmp/hsperfdata_root/3645
32      /tmp/hsperfdata_root/963
32      /tmp/hsperfdata_root/4034
32      /tmp/hsperfdata_root/11619
32      /tmp/hsperfdata_root/18122
32      /tmp/hsperfdata_root/12567
32      /tmp/hsperfdata_root/3820
260     /tmp/hsperfdata_root
4       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8       /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4       /tmp/.Test-unix
0       /tmp/wrapper-680-1-in
4       /tmp/.X11-unix
0       /tmp/wrapper-680-1-out
300     /tmp

Command Details: With the'-a'option, you can list and print disk usage for each file, including directories and subdirectories. This command identifies the largest file/folder in a given path and helps you delete/clear unused or largest files to provide sufficient free space for the server. In the example above, you can see the difference from the previous example, where each file, including the directory, is listed. If you add the'-h'flag to the command above, such as'du-ah', all output is in a human readable format.

du -c

List total disk space occupied by files

[root@hadoop3 /]# du -ch /tmp
4.0K    /tmp/.font-unix
4.0K    /tmp/.ICE-unix
4.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4.0K    /tmp/.XIM-unix
260K    /tmp/hsperfdata_root
4.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4.0K    /tmp/.Test-unix
4.0K    /tmp/.X11-unix
300K    /tmp
300K    total

Command details: Using the'-c'option will list the total disk space used at the bottom of the output. If you add the'-h'flag to the command above, such as'du-ch', all output is in a readable format.

du -BK/-BM/-BG

Output file/folder disk occupancy size in specified capacity units

[root@hadoop3 /]# du -BK /tmp
4K      /tmp/.font-unix
4K      /tmp/.ICE-unix
4K      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8K      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4K      /tmp/.XIM-unix
260K    /tmp/hsperfdata_root
4K      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8K      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4K      /tmp/.Test-unix
4K      /tmp/.X11-unix
300K    /tmp
[root@hadoop3 /]# du -BM /tmp
1M      /tmp/.font-unix
1M      /tmp/.ICE-unix
1M      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
1M      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
1M      /tmp/.XIM-unix
1M      /tmp/hsperfdata_root
1M      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
1M      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
1M      /tmp/.Test-unix
1M      /tmp/.X11-unix
1M      /tmp
[root@hadoop3 /]# du -BG /tmp
1G      /tmp/.font-unix
1G      /tmp/.ICE-unix
1G      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
1G      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
1G      /tmp/.XIM-unix
1G      /tmp/hsperfdata_root
1G      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
1G      /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
1G      /tmp/.Test-unix
1G      /tmp/.X11-unix
1G      /tmp

Command details: Combining the'-B'tag with'K','M' or'G', you can divide the total disk usage of files and directories into kilobytes (Kilobytes), megabytes (Megabytes), or gigabytes (Gigabytes). However, please note that when using capacity units, use them appropriately, otherwise this will happen, there is actually no 1M, using-BM will result in files rounding capacity.

du —max-depth=x

Check the size of all subdirectories in the current location

[root@hadoop3 /]# du -h --max-depth=1 /tmp
4.0K    /tmp/.font-unix
4.0K    /tmp/.ICE-unix
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4.0K    /tmp/.XIM-unix
260K    /tmp/hsperfdata_root
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4.0K    /tmp/.Test-unix
4.0K    /tmp/.X11-unix
300K    /tmp

Command Details: Add the'-max-depth=x'parameter to check the disk capacity size of the x-depth subdirectory in the current directory.

du —exclude="xxx"

Exclude specific types of files when calculating disk size

[root@hadoop3 /]# du -h --exclude="*.font-unix" /tmp
4.0K    /tmp/.ICE-unix
4.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4.0K    /tmp/.XIM-unix
260K    /tmp/hsperfdata_root
4.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8.0K    /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4.0K    /tmp/.Test-unix
4.0K    /tmp/.X11-unix
296K    /tmp

Command Details: Using the'-exclude'option in the'du' command, we can remove certain modes (such as php, txt, png extensions) when calculating disk usage for all files and directories.

du —time

View disk usage at last modification time

[root@hadoop3 /]# du -ha --time /tmp
4.0K    2021-02-26 12:19        /tmp/.font-unix
4.0K    2021-02-26 12:19        /tmp/.ICE-unix
4.0K    2021-11-20 23:29        /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ/tmp
8.0K    2021-11-20 23:29        /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-nginx.service-pt0CTJ
4.0K    2021-02-26 12:19        /tmp/.XIM-unix
32K     2021-12-06 00:17        /tmp/hsperfdata_root/5057
32K     2021-12-06 00:18        /tmp/hsperfdata_root/3645
32K     2021-12-06 00:17        /tmp/hsperfdata_root/963
32K     2021-12-06 00:18        /tmp/hsperfdata_root/4034
32K     2021-12-06 00:18        /tmp/hsperfdata_root/11619
32K     2021-12-06 00:18        /tmp/hsperfdata_root/18122
32K     2021-12-06 00:18        /tmp/hsperfdata_root/12567
32K     2021-12-06 00:18        /tmp/hsperfdata_root/3820
260K    2021-12-06 00:18        /tmp/hsperfdata_root
4.0K    2021-11-20 18:18        /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD/tmp
8.0K    2021-11-20 18:18        /tmp/systemd-private-31de4ddb230847ecb9b7d67391665ec2-chronyd.service-rVhZDD
4.0K    2021-02-26 12:19        /tmp/.Test-unix
0       2021-12-06 00:18        /tmp/wrapper-680-1-in
4.0K    2021-02-26 12:19        /tmp/.X11-unix
0       2021-12-06 00:18        /tmp/wrapper-680-1-out
300K    2021-12-06 00:18        /tmp

: Use the'time'option in the'du' command, which lists the date and time of the last modified file and directory.

Posted by ponsho on Sun, 05 Dec 2021 11:59:14 -0800

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