disk usage difference

[Shivkumar]

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

[James R. Ferguson · Accepted solution]

Hi Shiv:

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

Regards!

...JRF...

[Pete Randall]

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

[Jannik]

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 ./*

[Arunvijai_4]

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

[Nguyen Anh Tien]

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

[Arunvijai_4]

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

[Senthil Prabu.S_1]

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

[Devender Khatana]

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

[Yogeeraj_1]

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

[Shivkumar]

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.

[Shivkumar]

did anyone get a chance to see my reply ?

[Pete Randall]

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