kernel: journal commit I/O error
Solution 1:
I've seen those errors before, but not during the install process.
It means that the drive got enough errors that the OS took it to read-only mode. If you could find the full logs, there'd probably be some I/O errors that retried and worked before the full-on failure errors you saw. Something with actual blocks mentioned.
It's a storage system error. It's definitely the RAID card, the drives in the RAID array, the cables from the card to the drives, the backplane the drives connect to, the slot the raid card is plugged into, the power supply for the hard drives, or something else in between the CPU and the actual storage blocks.
Solution 2:
Three possibilities come to mind:
There's memory problems (they often cause "random" crashes). If you have ECC ram in there, then obviously it's less likely.
There some problem with the Bus. I've had the same problem with a broken APIC controller on a Tyan dual Opteron motherboard a few years back. There were other log entries that hinted at it, but the bulk of the symptoms were random corruption on disk drives with automatic read-only remounts. In my case I knew it wasn't disk related because it was an external FC RAID box and it was fine.
The RAID controller is bunk.
This is in the order I'd consider the problems.
Solution 3:
It could be the RAID controller going bad like you said (try a spare if you have one.) It could be the driver for the controller (check for alternative drivers if available, even if performance is worse, it's good to have a reference point.) It could be the kernel (less likely though in RHEL, it's quite well tested.) It could be bad RAM messing up the block cache.
A hardware problem is the most likely cause, though, based on the seemingly random error behavior.
Solution 4:
Check that the disk isn't full - in particular the root partition. Use df to see the files system disk usage:
df -h
Look for partitions near or equal to 100% utilization