great piece of scolding of the darn /etc/security/limits.d
https://bugzilla.redhat.com/show_bug.cgi?id=919793

Danger of rebuilding a machine with lots of SAN disks in RHEL

This could be a disastrous situation. Say you were asked to rebuild a box from some decommissed box. and Volia someone didn't ummap the SAN disks during the decom process. Not thinking to check and trusting your colleague. You rebuild it via PXE or an ISO image. then... you discovered the OS picked one of the SAN disks to install the OS. If the disk is part of a live database, doesn't matter if there is I/O fencing set up on the cluster. The data is not protected and the database would be corrupted...
The morale?
boot with blacklisting the HBA drivers, common ones are qla2xxx or lpfc at the boot prompt.
"blacklist=qla2xxx,lpfc"

PXE needs to be fixed....

/dev/cciss are not there any more in RHEL6

Surprise! Another change from RHEL5 to RHEL6. the local HD is not /dev/cciss/c0d0 any more! it is /dev/sda

why?
check out https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Technical_Notes/ar01s09s02.html?

Redhat "Enterprise"

Guess what, Pam debugging can't be toggled in RHEL4-6!  it has to be changed at "BUILD TIME"!!!!! LOL

From Redhat:

The PAM stack implementation does not allow run-time debug toggling. Debugging must be enabled or disabled at build time.

Please take out the "enterprise" bit in your name.... RHEL!