tmp space question

we have been having problems with our disk space not being released by the engine. we have a sun 690 running 5.0 online. several times we've had the case that one of the mounted devices would become 100% full. we looked at all the files for size, creation time, etc. and nothing had changed that would have eaten up 100+ MB of disk space. this has happened to the home directory device as well as the /tmp device. ls -lt and du -s both said nothing had changed on those devices. in all cases, users were accessing the databases and were asked to log out. still no change in the free space on the device. the next step was to shut down the online engine. at this point, the space was freed up. im talking about 100's of MB and random devices. anyone else see this? whats going on? on the unix side, what should i look for when this is happening? thanks in advance, ------------------------------------------------------------------------------ | . . Bob Baskett | ... ... Software Engineer, DBA | ..... ..... Business Systems Integration Group | .. ... .. Semiconductor Products Sector | . . . Mesa, AZ | | Motorola, Inc ------------------------------------------------------------------------------