News

posted on 10 June 2008 07:25

NetApp has announced PCIe-fit Performance Acceleration Modules (PAM) to boost the performance of its FAS and V-Series storage products.

A PAM is an intelligent read cache card and plugs into a FAS controller's PCIe bus to provide 16GB of DRAM, extending the original DRAM cache (equivalent to main memory) in the controllers. A FAS 6000 could have 32GB of such DRAM and up to five PAMS can be added to provide a total of 112GB of DRAM.

Logically it sits between main memory and disk and functions as a disk read I/O accelerator.

NetApp's EMEA Solutions Marketing Manager, John Rollason, said one PAM can provide the equivalent number of IOPS as 16 Fibre Channel hard drives.

Rollason added that this provides a new dimension of scaling, complementing scaling up from FAS controller to controller (product to product), scaling storage capacity, and, now, scaling internally by adding PAM boosters. He said that: "with the PAM you can avoid short-stroking disks."

Both Pillar Data and Compellent place the most active data in their storage products on the outer tracks of hard drives to increase performance. Other disk storage suppliers' products can deliberately place date on the outer tracks and not use the inner tracks at all in storage I/O-bound applications.

NetApp's Data ONTAP array operating system provides Predictive Cache Statistics, introduced in ONTAP 7.2.1, and these can be used to guide customers to the best scaling method as their storage workloads increase. If these statistics show a high proportion of random reads are ocurring then PAM cards could be the best scaling choice.

Rollason said that PAMs could be: "interesting for deduplication workloads"

Other vendors are choosing to boost storage array I/O through a flash memory solid state disk (SSD) tier of storage, with EMC already shipping and HDS announcing this as a strategy. Sun is choosing to embed SSD caches between a server's main memory and its direct-attached disks. What does NetApp think of SSD technology?

Rollason said: "There is a place for them over time (but) there are things we need to work on to make use of SSDs. The algorithms for making use of DRAM are much better understood."

The U.S. list price for the Performance Acceleration Module is $15,000, and the software for the module is $20,000. (One software license is required for each storage controller. Between 1 and 5 modules can be installed in the storage controller, depending on the model. So the first module costs $35k and subsequent modules cost $15k each, up to the maximum number supported by the particular storage controller.)

Separately NetApp has introduced a Storage Acceleration Appliance which acts as a cache in front of storage arrays, and boosted the performance of its mid-range FAS 3000 line with new FAS3140 and 3170 models that are up to 40 percent faster.

^{[Chris Mellor.]}