Questions on utilizing UUIDs and UDEV for RHEL VMs that live on SAN

So I have some questions based on doing some research here on Red Hat Customer Portal and this is due to some issues with one of our SANs which caused a number of data disks on the VM to shuffle out of order on a RHEL 5.11 server that houses Oracle and Oracle ASM. We couldn't fix the issue as the UUIDs dropped from the partitions that were on that SAN, and we had to fall back to backup tape.

I'll also state that I've had no real training for SAN technology, other than jumping in with it, shadowing those who have more experience and knowledge then me, and asking lots of questions. 99% of those folks I shadow only know Windows OS stuff and have no clue when it comes to Linux things, so I have to be the expert.

First, I don't believe that I need to do anything special on the RHEL VM side for the OS to access data that is mapped to the SAN, correct? I don't believe there is a need for multipathing, how do I even know if that is enabled? Or if its even needed?

Second, since the RHEL VMs are using SAN disk, its seems wiser to use UUID then say /dev/sdX, correct? I'm thinking that is one of the reasons why those disk on that RHEL VM was scrambled because they couldn't reference anything back on the SAN? Right now, I'm in the process of converting entries in /etc/fstab to UUID, however I want to be certain on this.

And third, we have some RHEL servers that use OracleASM and it looks like that entries have to be made in udev. I'm reading thru this previous thread here, trying to make sense of it:

https://access.redhat.com/discussions/876913

Right now I have a RHEL 5.11 system we are trying to convert to to RHEL6 which is using Oracle ASM to manage disks that live on SAN. I'm just trying to figure out the best way to to set this up correctly. I'm sure I'll have more questions.

thanks