There is no option to allow only reads from potenially bad luns. You may only disable specific paths or all paths for a lun (vxdmpadm disable path=<pathname>).
Also, you may consider Removing and Replacing the failing Disks
I believe you should be atleast on SF ver 6.0.5 for sol 11.2 to be supported.
see 'Supported platform version':@
Are you seeing the luns alright at the OS level on Solarisc currently? (cfgadm -al)
Can you clarify more on "before re-install, the two nodes are in one cluster." what was the OS in this 2-node cluster initially and what was the SF version initiall...
You could make use of "vxdiskadm" to manage the process of replacing the failed boot disk -which is not evident from the steps you've mentioned above. (some sample screen o/p here). Also, please double-check if the replacement disk used for the faile...
For HP-UX 11.31, the list of patches that are installed with 51SP1_RP3 are mentioned on page 15 of the release notes: