topic why bdf & du display two different results in Operating System - HP-UX

why bdf & du display two different results

王曦_1 — Fri, 13 Jun 2003 01:32:58 GMT

hi expert,
i found my /opt is 100% full by bdf command, and i could not copy any file to this filesystem, but when i use df -sk, i found the filesystem only 67% full, how can i do
thanks

Re: why bdf & du display two different results

Rajeev Shukla — Fri, 13 Jun 2003 01:38:03 GMT

your /opt might be full because of inodes too.

best it to unmount and mount /opt again that will help or reboot the system if its not critical and if it so take an outage and then do it.
/opt being full wont anyway bother your normal execution of machine.

Rajeev

Re: why bdf & du display two different results

Michael Tully — Fri, 13 Jun 2003 01:39:16 GMT

Have you attempted to remove some largefiles?

These files could still have some processes open and that is why the report is incorrect.

Regards
Michael
"When I have trouble spelling, it's called fat finger syndrome"

Re: why bdf & du display two different results

Steven E. Protter — Fri, 13 Jun 2003 01:41:04 GMT

If there are open processes on files you recently deleted, bdf will show the filesystem is full even though you just deleted a bunch of files.

du will show the space as clear.

Since /opt is not such a critical filesystem, you can clear this without a boot.

fuser -cu /opt

to identify the processes.

fuser -cuk /opt to just go ahead and kill all open processes on /opt

After running the second command, bdf and du -sk should show similar results.

SEP

Re: why bdf & du display two different results

V.Tamilvanan — Fri, 13 Jun 2003 01:43:22 GMT

Hi,

When a process writes to a file if you have removed that file forcefully before that file closed by that process, you see the difference between bdf and du -sk.
The information is updated immediately to the du -sk but not to bdf.
If you restart your server the bdf output will be updated properly.
Check by using lsof whether any process writes to the /opt FS and you can kill that process. By doing this also ur bdf may get updated.
HTH

Re: why bdf & du display two different results

V.Tamilvanan — Fri, 13 Jun 2003 01:45:42 GMT

Hi,
Have a look at this thread

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x408f44f56197d711abdc0090277a778c,00.html

Re: why bdf & du display two different results

twang — Fri, 13 Jun 2003 03:05:00 GMT

du shows the number of currently allocated blocks.
bdf shows the free disk space available.

The difference is because bdf cannot see the blocks "occupied" by a still active process.
bdf will see the change until the process terminates.

Re: why bdf & du display two different results

Helen French — Fri, 13 Jun 2003 03:23:02 GMT

The questions regarding bdf and du has been answered almost every day! Please do a search on the forums (now on top of the screen) and find the best solution available for you.

Re: why bdf & du display two different results

Caesar_3 — Fri, 13 Jun 2003 06:12:20 GMT

Hello!

The bdf and du work on diffrent system calls
So if one proccess write to that file system
with du you would see the size that it take
and with bdf you will see.

Also see in man about the block size that
the command show the size.

Caesar