Nothing is showing unusual in the maintenance logs at or around the times these occur.
This is the part that is really unusual. What is strange is if I perform scheduled reboots of these systems say weekly the problem is not seen, but as soon as you stop this and let it go a couple of weeks the issue is seen again.
Our company does not like to do reboots because we run 24x7 and this causes interruption of services.
Thank you