AIX

i have an aix5.3 box with a full /tmp. i emptied the tmp directory and still doesnt change from 100%. if i try to increase the /tmp size it keeps on wanting me to delete more files in the directory.
what can i do.i'm still learning aix

You deleted a file that is being accessed. A process keeps the file open and while you cannot see it any longer with ls command it is still there. You need to stop/restart the process to free the empty space. Either reboot or kill the process in question. From outside /tmp as root try
# fuser -xuc /tmp
You might get some process ID in return. (If you don't get lsof and try again). Check the processes (omit trailing characters) and if possible kill it/them. Don't do this with RSCT or HACMP based daemon processes as that might crash your server.
Next time check usage of files in /tmp first. It is possible to free space by overwriting the file while it is in use. You can always do
# cat /dev/null > /tmp/yourbigfile
or, as an AIX admin you'd rather do
# > /tmp/yourbigfile

Just Run the below command and send me the output of big files.

find /tmp -xdev -type f -ls|sort -nr +6|head -30
it can be helpfull to analyse this issue
as well as please send me the error messages what you are getting if you are trying to extend the size os /tmp

use the command:
lsvg rootvg
to determine the free space in rootvg
then run chfs -a size=+<size by what you want to extend> /tmp

thanx a lot, i finally rebooted the server and it did the trick. the /temp is free