By Dave Simpson
Dataram announced its XcelaSAN accelerator well over a year ago, and has been shipping single-unit configurations for some time, but today the company announced a redundant, high availability (HA) version of the Fibre Channel SAN accelerator appliances – the XcelaSAN model 100 – that eliminates the single point of failure.
The basic “speeds and feeds” of the appliances have not changed since their introduction in late 2009 (see “Dataram accelerates FC SANs”), except that the company has doubled the amount of flash memory in the appliances. Each solid-state appliance has 120GB of DRAM cache and 600GB of multi-level cell (MLC) NAND flash memory for persistency. Due to RAID mirroring, 300GB of the flash capacity is usable.
XcelaSAN appliances have eight 4Gbps Fibre Channel ports. In a dual-unit configuration, that translates into 14 usable ports since two ports are used for communications between coupled appliances.
Dataram is conducting ongoing performance testing, but Jason Caulkins, Dataram’s chief technologist, claims about 3GBps of throughput and 450,000 I/Os per second (IOPS) per appliance.
Other features of the XcelaSAN appliances include write coalescing and write avoidance.
Caulkins says that, although the SAN accelerators could be used in low-end SANs, the company is primarily targeting mid-range SANs, which he characterizes as storage networks with disk arrays such as EMC Clariion, HP EVA, IBM DS and NetApp FAS arrays.
The XcelaSAN accelerator is priced at $65,000.
In a survey of Fibre Channel SAN users commissioned by Dataram, nearly half (48%) of the users said that they address performance issues by adding more disk arrays/spindles. Another 45% said that they were considering solid-state devices to solve performance problems, although only 15% have implemented solid-state devices.