Grid Infra version: 11.2.0.4
Platform: Oracle Linux
http://docs.oracle.com/cd/E11882_01/server.112/e18951/asmdiskgrps.htm#OSTMG13711
Question1.
We use Enterprise class storage from Hitachi Data Systems called VSP for our diskgroup LUNs. They provided frame(hardware) level RAID protection. Hitachi SAN admins confirmed that the LUNs they allocate are created our disks from different failure groups. In this case , do we need to use High or Normal redundancy ?
Question2.
We are going to build a 3 node RAC cluster for a very critical application. For the +OCR_VOTE diskgroup, we are going to use LUNs from Hitachi VSP. SAN admins are going to allocate 1GB LUNs for this. In addition to the hardware level protection provided by Hitachi , we would like to have an ASM level redundancy as well. We prefer High Redundancy for +OCR_VOTE diskgroup. So, how many 1GB LUNs will be required for this ? How is this calculation done ? The above oracle documentation just says "three way mirroring" for High redundancy , does this mean, that, to protect data in a 1GB LUN we need another three 1GB LUNs (total four 1GB LUNs ) for High Redundancy ?