Does bdf and du give a bad result ?

[Abdul Majeed Lardhi]

In the morning the free space precentage was 37% in oracle file system "/dbase/u00"

after an hour the file system growed fast and reached to 97% then we did not find any files updating or changing upnormal on this file system
see the du and bdf :
/dbase/u00 (/dev/vgfnsd3_r1/lvu00): 772448 blocks 72747 i-nodes
/dev/vgfnsd3_r1/lvu00
9216000 8933050 282950 97% /dbase/u00

We afraid the system to hang so stop all the application running and oracle before Suddenlly the file system free precentage return back to normal 37% !!! ( without rebooting )

see the du and bdf :
/dbase/u00 (/dev/vgfnsd3_r1/lvu00): 11458180 blocks 736881 i-nodes
/dev/vgfnsd3_r1/lvu00
9216000 3320890 5729090 37% /dbase/u00

Really it confusing me !!!

Any one have seen or heard about this problem ?? and how to fix it ??

Regards

[Bill McNAMARA_1]

this is discussed here:
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x308b402f24d5d61190050090279cd0f9,00.html

Later,
Bill

[Armin Feller]

Hi,

if du and bdf shows different results, it seams that somewhere has removed files where which are accessed during remove. To find this processes and kill them you can do following:

# lsof +aL1
# kill

lsof can be downloaded by:

http://hpux.asknet.de/hppd/hpux/Sysadmin/lsof-4.64/

Best regards,
Armin

[Niraj Kumar Verma]

Hi,

There may be a chance that some process will be holding your space.

are you running any backup or dump ???

-Niraj

[Armin Feller]

Obviously there is a difference how du and bdf count. This may occur if we touch open files.
"du" offers in a way a positive view: it shows the number of currently allocated blocks and counts the blocks you've just deleted as free.
"bdf" has a more negative perspective: it shows the free disk space available.

The difference is here: if a still active process allocated blocks eg for a logfile that you've just deleted "bdf" counts these as still occupied. This wont change until the process closes the file ("deallocates the blocks") as it usually happens when the process terminates.