What is Vault drive?

The Vault is where the OS for the array lives. In the case of Clariion and Celerra we are talking about the FLARE and DART code that enables the array to do its thing. Up until now this has always been the 1st 5 drives in the array – Drive Slots 0 – 4. These disks were setup as a 4+1 R5 Raid Group on which the FLARE/DART took up a small about of space on each drive. The remaining space could be used just not for any high I/O loads. Drive size was up to you but pretty much any drive size/type would work.