[John Russell]

EqualLogic is a block (iSCSI) rather than a NAS solution, so a very different beast to Isilon. It does offer some limited scale out, but like similar ‘scale-out’ iSCSI such as HP LeftHand once you have a couple of dozen nodes management and performance start to become ‘challenging’.
Isilon is not for people who buy just on cost per GB, but rather it does three things really well: scales capacity (up to >20PB in a single files system), scales performance (many many GB/s) and is very easy to manage. Very little, if anything else, does all three well. For that capability there is a cost, so not for everyone, but from a pure NAS perspective it is perhaps the coolest tech out there.

Cheers,

JR