[ILUG] Disk utilisation oddity

[Niall O Broin]

On 26 Mar 2006, at 12:03, kevin lyda wrote:

> On Sun, Mar 26, 2006 at 12:58:37AM +0000, Niall O Broin wrote:
>>> second, perhaps the backups between the two systems create a lot of
>>> temp files in the standby sysyem?  once allocated it doesn't seem  
>>> like
>>> space in dirs is reclaimed.
>> No, it's not, but none of the directories here have ever been large -
>> they're all only one block (4096b).
>
> well this is what i see:
>
>     : kevin at ogunquit on pts/3 ; mkdir bob
>     : ok ; : Sun 26 0:27 ; cd ~
>     : kevin at ogunquit on pts/3 ; ls -ld bob
>     drwxr-xr-x  2 kevin kevin 4096 2006-03-26 00:27 bob
>     : ok ; : Sun 26 0:27 ; cd ~
>     : kevin at ogunquit on pts/3 ; seq -f 'bob/%g' 1 2000|xargs touch
>     : ok ; : Sun 26 0:28 ; cd ~
>     : kevin at ogunquit on pts/3 ; ls -ld bob
>     drwxr-xr-x  2 kevin kevin 24576 2006-03-26 00:28 bob
>     : ok ; : Sun 26 0:28 ; cd ~
>     : kevin at ogunquit on pts/3 ; seq -f 'bob/%g' 1 2000|xargs rm
>     : ok ; : Sun 26 0:28 ; cd ~
>     : kevin at ogunquit on pts/3 ; ls -ld bob
>     drwxr-xr-x  2 kevin kevin 24576 2006-03-26 00:28 bob
>     : ok ; : Sun 26 0:28 ; cd ~

This is very interesting Kevin, and a known artefact of Unix  
filesystems, because a directory is simply a file, and a file which  
gets bigger the more subdirectories it has, and it seems that no Unix  
ever bothered with shrinking directory files if they needed less space.

But what has it got to do with my question - I explained that none of  
the directories involved are large and anyway, 800MB of directory  
space would be rather a lot.


Niall