PRVF-5150 : Path /dev/oracleasm/disks/DISK_NAME is not a valid path on all nodesappears in the OUI but running cluvfy -pre crsinst shows that all pre-reqs are successful. If the ASM setup is validated as per 1210863.1 then this pre-req failure on OUI could be ignored and installation could continue.
Useful metalink notes
Grid installation reports error on "Prerequisite checks" PRVF -5150 [ID 1498115.1]
Device Checks for ASM Fails with PRVF-5150: Path ORCL:
Bug 14048512 - PRVF-5150 : Path ORCL:DISK1 is not a valid path on all nodes [ID 14048512.8]
GI 11.2.0.3 Installation On Errors PRVF-5150 saying ASMLIB path is not a valid path [ID 1474961.1]