Dot Hill starts Software RAID
AMD links up via Southbridge
Disk array subsystem supplier Dot Hill is selling a software RAID product to run on multi-core processors.
In keeping with its selling of disk array products to original equipment manufacturers (OEMs) Dot Hill is supplying its Virtual RAID Adapter (VRA) software in its RAIDCore line to OEMs as well. In fact, AMD has signed up for it, with the VRA software available for AMD’s newest SP5100 Southbridge chipset.
Dot Hill's notion is to help volume server OEMs or ODMs (original design manufacturers) offer built-in RAID functionality without the expense of a dedicated RAID-on-chip acceleration device. They can just use a spare core in the multi-core CPU instead.
Rorke Data announced a similar product in April.
Dot Hill acquired some assets from Ciprico in September 2008, which included exclusive rights to license RAIDCore technology from Broadcom Corporation. Dot Hill says: "The acquisition was part of a strategic initiative to offer software-only products for the enterprise server data protection market, as a complementary offering to its existing external hardware RAID array business."
It reckons that using SW RAID and multi-core CPUs means RAID can be offered in volume, entry-level servers, where hardware-accelerated RAID has traditionally been too expensive. Dot Hill comment: "With today’s multi-core servers priced as low as $400, there is a... need for RAID functionality that offers high performance at a compelling price point. Up until now, customers only had a choice of pricey hardware controller-based add-in RAID cards, which can cost as much as the server hardware itself, or more budget-conscious, core logic chipset-based RAID solutions, which provide fewer features and are unable to meet the stringent demands of 24/7 server-class RAID technology."
VRA enables host-based RAID 0, 1, 5, 10 and 50 directly on motherboard SATA I/O ports, but not RAID 6. The same software stack, with additional features enabled, can also be used for higher end SAS disk-based systems that employ a built-in or PCIe host adapter-based SAS/SATA chipset, enabling vendors to maintain compatibility and a consistent look and feel across the entire product line.
The VRA software supports Windows and Linux Intel-compatible servers’ SATA I/O ports, as well as I/O ports on SAS/SATA add-on controllers. Dot Hill says VRA has "superior write-performance over other software and hardware-based server RAID" products because of its "innovative caching technology." It offers enhanced functions such as mirroring schemes to support simple system backup and recovery.
Dot Hill claims to have fixed many software RAID problems, such as boot drive protection and fast recovery from system power loss. It calls VRA a universal RAID driver, and says it supports multiple disk controllers and can cope with SAS expander technology, lots of small form factor 2.5-inch drives, and server-connected JBOD arrays.
The SW enables functions such as online RAID-level migration, online capacity expansion, background scrubbing and consistency checking, which Dot Hill claims are historically the domain of hardware RAID implementations.
OEMs can offer a base set of RAID features with a purchasable license key opening up more functions. There's more information available here. ®
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