IBM's Exadata2 knock-off could use SVC and flash

Comment IBM's DB2 Pure Scale project has a storage problem - storage arrays don't make good cluster nodes.

Pure Scale is the rumoured Exadata 2-killer from IBM. It is thought to be a clustered implementation of IBM's DB2 database running on Power-based servers with the AIX O/S, and an InfiniBand cluster interconnect between server and storage nodes.

It will use InfiniBand's Remote Direct Memory Access (RDMA) features to give nodes access to each other's data for processing. There will be a designated head node server to manage the locking of database fields as transactions and queries are processed and the locking/unlocking of memory of all nodes in the cluster.

Fair enough. The problems we at El Reg Analyst Towers see is that a) your bog-standard storage array controller is not a cluster node, b) it doesn't have an InfiniBand (IB) link, and c) Exadata 2 relies on flash for its performance. Step forward IBM's SAN Volume Controller (SVC).

This is the dedicated box that sits in a SAN fabric, virtualises the SAN storage arrays and presents them to accessing servers as a virtual storage pool. In Project Quicksilver, IBM and Fusion-io demonstrated a million IOPS from an SVC set-up accessing lots of Fusion-io's ioDrive NAND flash solid state storage cards, 40 of them in fact.

Texas Memory Systems' RamSan flash storage is also available for the SVC.

That could provide the missing flash ingredient. What about an IB link? IBM'r D S Guthridge produced a paper last year entitled "Scalable, high performance InfiniBand-attached SAN Volume Controller" that described how: "Large read performance from SVC cache exceeds 3GB/sec in a minimal two-node cluster configuration," with an InfiniBand host attached system.

If IBM were to somewhat hurriedly cook up an Oracle Exadata knock-off product then IBM-connected SVC nodes with Fusion-io or TMS flash could be part of a back-of-an-envelope hardware spec. ®