VMware has come up with new vStorage APIs in vSphere 4.1 that improve storage array's abilities to store lots of virtual machines (VM), copy them, and help move them; great for VMware users; potentially terrible for some array vendors. Maritz' developers seem to have modelled much of the new vStorage properties on pioneering …
and no mention of VMWare's bestest best buddy daddy EMC?
So here the fun starts - VMWare unlike the OS world have realised that they can influence external storage development i.e that which is in the arrays, and this will dramatically show up the difference between those with real functions and those with none or tickbox implementations.
It is also a strategic move for VMWare against particularly Hyper-V which comes form a MS background of treating all storage as dumb DAS
EMC - supports SIOC
Disclosure - EMCer here.
Chris, FYI - EMC supports SIOC (in fact any block storage target on VMware's HCL supports it - as it's a VMware feature, not an array feature - hence our focus on VAAI which actually requires us to actually do something to support it).
SIOC is aligned with autotiering (from us and others) - with SIOC resolving instantaneous contention conditions through prioritized throttling, and auto-tiering resolving the ongoing issue of VMs with different IO loads on the same datastore.