What type of RAID volume would be the best type to use for a VMFS Volume on my ESXi Hosts. I will be using iSCSI shared storage between a cluster. I have the options of 0,1,5,1+0. I have narrowed down my decision to 1+0 or 5.
It really will depend on the kind of VMs you will be running. Are the applications write heavy or read heavy?
Read heavy systems will be ok on a RAID-5, while RAID-10 (1+0) will be much faster on writes. The parity calculation with raid 5 takes a beating to RAID-5.
RAID-10 also has the disadvantage of using half of your storage for redundancy.
RAID-5 will really need a battery-backed cache for any decent performance.
I am using RAID-10 on an Openfiler SAN at work and it works nicely as the app is very write heavy.
It depends on a lot of factors which you havent provided.
However 1+0 offers the great performance and high availability, at the cost of losing the more disk capacity than RAID 5.