Any chance a machine is running out of space?

Can't say for sure, the machine's instalation is gone; what I know is that those mainframes (virtualized) tend to have only 26 GB of disk space so it's not impossible to run out of space.

Sys_resource means one of the following was hit.

/* Override resource limits. Set resource limits. */
/* Override quota limits. */
/* Override reserved space on ext2 filesystem */
/* Modify data journaling mode on ext3 filesystem (uses journaling
   resources) */
/* NOTE: ext2 honors fsuid when checking for resource overrides, so
   you can override using fsuid too */
/* Override size restrictions on IPC message queues */
/* Allow more than 64hz interrupts from the real-time clock */
/* Override max number of consoles on console allocation */
/* Override max number of keymaps */


We do not usually allow confined applications to override resource constraints.

If this is happening to lots of domains, it it a kernel issue.  These apps should not require sys_resource unless the system is running out of resources.  

I think there is a bug in s390x that is causing bogus sys_resource capability checks.

If you want to stop them, you can add policy that says

allow domain self:capability sys_resource;

Since RHEL 6.2 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

Since RHEL 6.3 External Beta has begun, and this bug remains
unresolved, it has been rejected as it is not proposed as
exception or blocker.

Red Hat invites you to ask your support representative to
propose this request, if appropriate and relevant, in the
next release of Red Hat Enterprise Linux.

It seems that the reported issue has not happened again, 
therefore, close this issue off as worksforme.