I have an OELv6 server which is regularly seeing Load Averages going to 20+ and when running "df -h" nothing returns. However "df -h /" (and other filesystems) will return with stats expected. I also usually see a CPU will run at 100% but there are 6 CPUs on this server so one running at full capacity from time to time isn't a problem. I dont think the fully utilised CPU is causing the high load averages. Users are seeing a big performance drop on this server when the load average goes high and this seems to be happening every few minutes, then the performance drops back to normal with the lower load average. Can't find a process which seems to be causing the issue. Had storage checked as well, it doesn't seem to be that. "dd" command tests dont highlight anything obvious.

Anyone have any thoughts or ideas please? I've got a call open with Oracle Support but I'm not getting anywhere fast with that so far.

Thanks.

what is in the system logs ?

/var/log/???

Certainly I/O related, and certainly no log messages
Run
And see at which file system it blocks.

Certainly ?.
Given the absence of hard data from the OP ?.

Extreme loadavg aren't always I/O, especially where Oracle and/or Apache are involved. And we don't even know that. At a minimum we need sysstat, and better something like collectl or collectd.