Isilon uses a scale-out architecture, which allows administrators to add more nodes to the system, increasing storage, compute power, and cache memory. By contrast, scale-up architectures can add drives to the platform, but the storage system's performance may be limited.
"Scale-up can bottleneck at the controller, so the more drives you put on them, you reach a point of diminishing returns," says Howard Marks, chief scientist at consultancy Deep Storage and an InformationWeek Analytics analyst. "You reach the max number of I/Os per second that the controller can handle, so adding drives doesn't help with performance."
"In scale out, when you add a node, you add compute power and drives and cache memory. If you need performance you can add faster drives, and if you need capacity, you can add nodes with more space." However, scale-out can also be more expensive than scale-up systems.
Marks says the new SmartLock feature with Write Once Read Many (WORM) storage makes sense for Isilon, which sells to customers with significant compliance concerns, such as the medical and pharmaceutical industries. "This is a feature that NetApp has had, so Isilon is adding WORM too," says Marks. "WORM isn't a big market, but those who are in it have deep pockets--when you need it, you're willing to pay a lot for it."
The new Isilon platform uses 3TB SATA drives from Hitachi, and can support up to 144 drives. The product also supports key software features such as tiering, which lets administrators move data among higher- and lower-performance drives, and asynchronous replication. The product is shipping now, with a list price of $123,500 per node. The SmartLock feature lists for $1,950 per node. EMC acquired Isilon in 2010 for $2.25 billion. The acquisition put the storage giant in better position against rival NetApp in the NAS market.