How to know the directory size in CENTOS [duplicate]

Under any linux system, you want to use the command du. (Disk Usage)

Common usage is : du -sh file(s) name(s) or du -sh /path/to/dir/*

-s stand for "summary" which will give you the size of each argument instead of detailing th size of each elements of the file tree underneath.

Replace 'h' by 'k','m' or 'g' for Kilobytes, Megabytes and Gigabytes instead of human-readable. With k/m/g switches, you can then pipe the output to sort -n (numeric sort instead of lexicographic) to get the sorted by size list of files in a directory. sort even has a -h filter on latest versions.

If you still have a big difference, you may want to try the --apparent-size switch to du which will allow you to diagnose sparse files. (files with empty space inside, to be simple)

For more information, see the manual page of du