The Vault drives are the first 4 drives in the AX4-5 (0,1,2,3). You can identify them by the little yellow stickers that warn you not to move the drives from their location. And you shouldn’t. The Vault drives contain OS, config and other information. If you pull these drives from the system, it will not fully boot (you can still connect via serial). If these drives fail in a certain sequence, the same fate will ensue. Simply put, you need them to be healthy.  Should I separate the Vault Drives (1st 4 drives) into their own RAID Array? Yes, EMC does not recommend binding the luns on the vault area.    EMC does not recommend creating a large RG in which you include the vault area drives also as the vault area handles already Boot Partition, Primary boot disk, Secondary boot disk, Utility Partition and many important functions of the OS. So even if there is a slight dip in performance it becomes very tedious to locate the lun/disk suffering from performance dip.  If later you realize that you need some more space then you can use your vault drive and may present it to the app that has low I/O's thats the best recommendation i can give.  Might help [IMAGE]      
Hi,  I am ready to set up a newly aquired CLARiiON AX4-5F with 2 ESXi 5.0 servers.  Having read through the following documents...  [URL]   [URL]   ... I'm unsure as to whether I should be setting aside drives for exclusive use as Vault Drives.   Also, if I leave the Vault Drives as part of my operational LUN, what is the impact in regards to size available from the remaining drives?  Perhaps I am being over cautious being a relative newbie to SAN technology.  I would be very intersted to hear opinions please.  Best regards, Steve
AX4-5F Vault Drives - Separate LUN?