PAM II, the second generation of the Performance Acceleration Module, builds on the DRAM-based PAM I, which plugged in the PCIe bus behind an array controller's main memory as a 16GB DRAM cache. PAM II has 256GB or 512GB of single level cell (SLC) NAND flash. NetApp array controllers can have 4TB of this in one controller with up to eight PAM II 8 cards. Previously controllers could only utilise up to five PAM I cards. The cards are designed by NetApp and built for it, not being Fusion-io-supplied.
O'Neal said that, by offering such a flash cache, NetApp did not have to work out which data to put in flash as it would have to do if it added SSDs to its disk shelves. He would not discuss when NetApp might, as it has promised, add SSDs to its drive arrays.
NetApp said PAM I cache hits lowered data access latency from the 10msecs of a disk access to slightly less than 1msec. It claimed an FAS 3140 fitted with a certain number of SATA drives and PAM I cards performed as well as the same array fitted with twice that number of 15,000rpm Fibre Channel drives. A 2008 SPECsfs2008 benchmark resulted in 40,011 ops/sec, with an overall response time of 2.75msec.
NetApp didn't provide directly comparable PAM I vs PAM II performance statistics or actual numbers.
Working from a presentation slide, it appears NetApp tested SPECsfs2008 performance on a FAS3160 with 224 FC drives and 16TB of hard drive capacity. It attained 60,000 ops/sec with a 4.4msec response time. Changing the configuration to 56 FC drives, 16TB of capacity, and putting a PAM card in each 3160 controller resulted in 60,000 ops/sec with a lower response time of 3.5msecs. This is not a published SPECsfs2008 result and we don't know the PAM II card capacity.
DS4243 disk shelf
This is a 4U shelf and offers 24 SAS or SATA drives with a maximum 24TB capacity and a 3Gbit/s SAS interface. It supports up to 48TB of storage, using 2TB drives, and a 48TB 6Gbit/s SAS product would be called a DS4486 product, not that one is being announced today.
Price and availability
Data ONTAP 8 will be available for early access (testing) for selected customers in September, with general availability in the fourth quarter. Existing ONTAP customers receive it at no charge. For a new customer, ONTAP 8 software is a component of the NetApp FAS or V-Series platform purchased. Total cost is based on the particular configuration each customer selects.
Pricing for NetApp Data Motion has not been finalized.
The PAM II card is scheduled to be available in September 2009. A 256GB one is estimated to cost $40,000, while a 512GB one has an estimated cost of $80,000. The software license for the new PAM cards is currently offered at no additional charge. The original PAM card has an estimated cost of $35,000 for the first card (including approximately $20,000 for the software license) and approximately $15,000 for each additional card up to the limit of the storage controller.
The entry price for the DS4243 disk shelf with twelve 500GB SATA drives is approximately $26,000. It is scheduled to be available in September 2009.
With ONTAP 8 NetApp is saying to all customers who want to be cloud service providers, of whatever sort, that it can work with diverse server estates, as it is already with T-Systems. It claims to offer a virtualised, scalable and efficient unified storage service, with API access for the servers for automated services and chargeback. It will extend Data Motion's interfaces to support VMotion at some time and it can greatly increase the general I/O capability of its arrays by adding heads to them, and greatly increase the read I/O capability of controllers by adding large flash caches to them.
NetApp's ONTAP 8 signals that it wants to be a big noise in cloud computing storage. It will not offer its own cloud services, as EMC is doing with Decho. NetApp will not be going into competition with its cloud-providing customers. ®