Directory size grows when creating/deleting thousands of files

[Daryl Lublink]

Run the attached bash script. ( it might cause wear and tear on your hard drive ).

What I expect should happen :

Folder size of test should be 4.0K like before I ran the test.

What actually happened :

Folder size is not 2.1M ( 2138112 bytes ).

There does not seem to be any way to recover the 2 megabytes lost and the only way to get the folder size back to 4.0K is to delete it and recreate it.

lsb_release -rd :
Description: Ubuntu 14.04.1 LTS
Release: 14.04

apt-cache policy linux-generic :
linux-generic:
  Installed: 3.13.0.35.42
  Candidate: 3.13.0.57.64
  Version table:
     3.13.0.57.64 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
 *** 3.13.0.35.42 0
        100 /var/lib/dpkg/status
     3.13.0.24.28 0
        500 http://us.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

This also affects other versions of Ubuntu, including but not limited to Ubuntu 10.04 and Ubuntu 12.04

[Joseph Salisbury (jsalisbury)]

If you delete a file, and space does not get freed, it's usually either because the file is still kept open, or there are other hardlinks to it.

Can you run:
lsof | grep deleted

[Daryl Lublink (dlublink)]

Even if the files are huge, the size of the folder doesn't change. If I create 100,000 5 byte files or 100,000 1mb files, the folder size is about 2mb after I delete all the files.

However, it should be noted that when using much bigger files ( 200mb+ ), the folder size can be slightly bigger, but it is not the size of the deleted files.

I added a modified script.

lsof | grep deleted shows nothing.