topic Re: confusion about disk space - where's my 5GB? in Operating System - Linux

confusion about disk space - where's my 5GB?

yyghp — Fri, 17 Nov 2006 12:05:32 GMT

I noticed there were a same disk space issue on three of our oracle 10g servers, running Red Hat Enterprise Linux 3.
When I use "df -h", I could see:
# df -h
Filesystem Size Used Avail Use% Mounted on
...
/dev/vg00/lv06 9.7G 8.2G 1.1G 90% /u01

Which showed /u01 had used 8.2GB.

While I checked with "du -ks":
# du -ks /u01
3139912 /u01
# du -hs /u01
2.9G /u01

( /u01 is an Oracle directory )
# du -hs /u01/app/oracle
2.9G /u01/app/oracle

It showed only 3GB!
Why? Where's the other 5GB?
Thanks!

Re: confusion about disk space - where's my 5GB?

Alpha977 — Fri, 17 Nov 2006 14:29:01 GMT

Hello!

have you checked with

"fdisk -l" ?
Is this disk "mounted"?

Re: confusion about disk space - where's my 5GB?

yyghp — Fri, 17 Nov 2006 15:30:02 GMT

Yeah, /u01 is mounted, that's why I can see the content under.
Thanks!

Re: confusion about disk space - where's my 5GB?

Heironimus — Fri, 17 Nov 2006 18:05:29 GMT

Usually a discrepancy between df and du is caused by some files having been deleted while a process is still holding them open. Until the process either exits or explicitly closes the file the space won't be freed, but the links in the filesystem are gone so you can't see or measure it.

lsof might help find open-but-unlinked files.

Re: confusion about disk space - where's my 5GB?

Steven E. Protter — Sat, 18 Nov 2006 13:24:41 GMT

Shalom,

Generally when this happens there is a process with a file handle on a file you deleted as sysadmin.

Kill the process and the space is recognized.

The different utils have been known to give inconsistent answers and normally a system boot clears this up.

SEP

Re: confusion about disk space - where's my 5GB?

yyghp — Sun, 19 Nov 2006 10:29:24 GMT

Thanks!
Yes, the space was released after restart the oracle services.
Points added!