topic Re: disk usage difference in Operating System - HP-UX

disk usage difference

Shivkumar — Tue, 17 Jan 2006 14:32:41 GMT

$du and $bdf on a file system gives different used and free disk space ?
What could be the issue ?

Re: disk usage difference

James R. Ferguson — Tue, 17 Jan 2006 14:38:29 GMT

Hi Shiv:

There is no issue. 'bdf' inclues some of the underlying filesystem structural overhead in its summation of used space.

Regards!

...JRF...

Re: disk usage difference

Pete Randall — Tue, 17 Jan 2006 14:38:39 GMT

Usually it's because an open file has been deleted and bdf will not report the space as unused until the process holding the file open has terminated. The du command reports the space as unused.

Pete

Re: disk usage difference

Jannik — Tue, 17 Jan 2006 14:39:50 GMT

it could be a double mount. I recomeed that U do a
lvdisplay -v | more
and se the size of the logical volume.
Remenber that du give output in byte if you don't specify -k this is the command:
du -sk ./*

Re: disk usage difference

Arunvijai_4 — Tue, 17 Jan 2006 22:56:49 GMT

Hi Shiv,

There is no issue since bdf reports from structural way of a FS. Also, do a "sync" before executing "bdf" and "du"

-Arun

Re: disk usage difference

Nguyen Anh Tien — Tue, 17 Jan 2006 23:04:46 GMT

Hmm. not any issue!
bdf - working with mouting file system
du- size of file (not mouting file system)
Recommend:
If you want to monitor how many percent of Phisical disk is currently use, you should use
#vgdisplay -v vgname
pay you attention on Free PE and Total PE on each PV (physical Volume).

bdf, du only monitor file system, file level.
HTH

Re: disk usage difference

Arunvijai_4 — Tue, 17 Jan 2006 23:07:02 GMT

Hi shiv,

There are no of threads discussed about this in ITRC. You may need to take a look at them,

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=767419
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=787308

-Arun

Re: disk usage difference

Senthil Prabu.S_1 — Tue, 17 Jan 2006 23:36:42 GMT

hi shiva,
there are not much difference.
bdf works with mouting file system and
du just shows size of file

Re: disk usage difference

Devender Khatana — Wed, 18 Jan 2006 01:22:48 GMT

Hi,

bdf shows the usage of the file system by the contents. Whereas du shows the content's size in total.

There may be a difference as the files in use may have been showing different size than actual in use. It is also quite possible that if some file in use has been deleted, then the size for this will not be listed in du whereas bdf will consider the full space as used, reason being the process has not yet released the space to file system.

HTH,
Devender

Re: disk usage difference

Yogeeraj_1 — Wed, 18 Jan 2006 03:51:34 GMT

hi,

see also:
http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&admit=-1335382922+1137574060762+28353475&docId=200000080063060

hope this helps!

kind regards
yogeeraj

Re: disk usage difference

Shivkumar — Wed, 18 Jan 2006 11:37:18 GMT

We saw the difference between these 2 command too much. du -sk showed 1gb in /opt/rose/ file system whereas bdf showed 13gb. the disk alert is configured with bdf command. also application stopped working when disk usage with bdf reached 100%. we killed unused java process and it released the disk space from 96% to 8%. we had 14gb in /opt/rose total. i am still confused why 2 java processes were using 12gb of disk space. i checked there were no zombies running on the system also.

Re: disk usage difference

Shivkumar — Fri, 20 Jan 2006 09:35:53 GMT

did anyone get a chance to see my reply ?

Re: disk usage difference

Pete Randall — Fri, 20 Jan 2006 09:40:35 GMT

You need to use a tool like lsof to see what process is creating these files. You can download lsof from here:

http://hpux.cs.utah.edu/hppd/hpux/Sysadmin/lsof-4.75/

Pete