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Re: Weird df info
On Thu, 14 Jan 1999, Alex Shnitman wrote:
>
> I did a small experiment to compare gzip and bzip2, and noticed a very
> strange thing with the reporting of free diskspace. "zz" is just a
> copy of the first 89 MB of /dev/zero. :-) Now look at this:
>
> alexsh:~> ls -l zz*
> -rw------- 1 alexsh alexsh 89088000 Jan 14 19:41 zz
> -rw-r--r-- 1 alexsh alexsh 6793 Jan 14 19:49 zz.bz2
> -rw-r--r-- 1 alexsh alexsh 86489 Jan 14 19:42 zz.gz
> alexsh:~> df
> Filesystem 1024-blocks Used Available Capacity Mounted on
> /dev/hda3 3369806 1160824 2174121 35% /
> /dev/hda1 819056 339904 479152 41% /dos
> alexsh:~> rm zz*
> alexsh:~> df
> Filesystem 1024-blocks Used Available Capacity Mounted on
> /dev/hda3 3369806 1073388 2261557 32% /
> /dev/hda1 819056 339904 479152 41% /dos
> alexsh:~> ls -l zz*
> ls: No match.
>
> What the hell is going on? Is there some compression the kernel is
> doing on filesystem data that I don't know about? FWIW I'm running
> 2.2.0-pre6. It's not a multiuser system and mine was the only activity
> when I did the experiment. Any ideas? Can anyone try it on their
> system and tell me if they get the same results?
I'm possibly missing something here... lemme recap:
[root@gump ~]# df .
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/hda2 2316190 902352 1294088 41% /
[root@gump ~]# dd if=/dev/zero of=zz.top bs=1024 count=50000
50000+0 records in
50000+0 records out
[root@gump ~]# ls -l zz.top
-rw-r--r-- 1 root root 51200000 Jan 14 13:32 zz.top
[root@gump ~]# df .
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/hda2 2316190 952549 1243891 43% /
[root@gump ~]# rm zz.top
rm: remove `zz.top'? y
[root@gump ~]# df .
Filesystem 1024-blocks Used Available Capacity Mounted on
/dev/hda2 2316190 902352 1294088 41% /
[root@gump ~]# bc
bc 1.05
Copyright 1991, 1992, 1993, 1994, 1997, 1998 Free Software Foundation,
Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'.
1294088 - 1243891
50197
2261557 - 2174121
87436
here are my 50 megs and here are your 90 megs and chage...
(and please remember that df counts a meg as 1024 blocks of 1024)
what seems to be the problem?
--
Ira Abramov ; whois:IA58 ; www.scso.com ; all around Linux enthusiast
`When you say "I wrote a program that crashed Windows", people just stare
at you blankly and say "Hey, I got those with the system, *for free*".'
(Linus Torvalds)