Rather than building RAID sets up from physical drives and then slicing them back into LUNs my dream array -- like Compellent Storage Centers, HP EVAs and 3PAR InServs among others -- I would build LUNs from blocks spread across a larger universe of available drives. Of course, this would enable thin provisioning, data protection across drives of dissimilar sizes, faster failed drive rebuilds, and spare capacity distributed across the array rather than spare drives. A long warranty, a la Xiotech Emprise, would be nice, but I'm not sure I want to give up hot swappable drives just yet.
It would also use RAM and Flash intelligently to accelerate access to my hot data. In addition to flash LUNs and automated tiering that moves hot data to SSDs on a block by block basis, my dream array would, like SUN's Readzilla, have a huge, 200-500GB, MLC flash read cache so that my file system metadata and the frequently accessed code in my VM images is cached.
Servers would access the array via 8Gbps FC and 10Gbps Ethernet with CEE/DCB support. The Ethernet ports would support both iSCSI and FCoE. The iSCSI implementation would let me choose whether I want to present each LUN as an individual target, Equallogic style, or the array as a single target with multiple LUNs like FC arrays do. While I'm dreaming I might even want an FCoE name server so servers could directly connect via FCoE without an FCoE switch.
Those Ethernet ports would also support both sync and async replication. This should include the ability for a pair of replicating arrays to both present the same LUN identity (Target and LUN, IQN Etc.) to servers the way Compellent's Live Volume or HDS' HAM so I can Vmotion a server from one data center to the other and have it always access its local array.
While I'm dreaming, lets include an iSCSI initiator that can connect to any other iSCSI array and do Asynchronous replication. Array vendors keep telling me they can replicate better and faster if they control both ends of the circuit, but I can't understand why someone doesn't offer a least common denominator replication protocol as open source and shame their competitors into supporting it.
