BY HEIDI BIGGAR
IBM's recently introduced Total-Storage NAS Gateway 500 is a single-processor configuration designed for small and medium-sized businesses (SMBs) and remote offices. The original NAS gateway, which was introduced in January, included two or four processors and was geared toward larger enterprises.
The lower-end gateway has the same feature set as the multi-processor versions but has a 40% lower entry price ($30,000 versus $50,000).
Users can scale performance and availability by adding processors as needed or by clustering the gateways. According to Vaughn, "This allows SMBs to start with a base configuration and 'pay as they grow.' "
"There's a general trend to bring networked storage into lower segments of the market," says Brad Nisbet, program manager for storage systems at International Data Corp. (IDC), a market research firm. "And even IBM, which focuses heavily on enterprise and data-center environments, recognizes [the opportunity] to provide storage solutions to a broader set of customers."
According to IDC, the market for NAS gateways is expected to grow at a compound annual growth rate of more than 46% through 2007.
A downside of the single-processor gateway, however, is the potential single point of failure it creates unless the gateway is clustered (or used in a remote mirroring configuration where high availability isn't mandatory). "The single-processor version isn't suitable for high-end environments, but it is okay for SMBs," says Vaughn. "And if they want high availability, they can cluster it."
IBM also expects organizations to use the high-end and low-end gateways in combination for disaster-recovery purposes. In this scenario, a two- or four-processor gateway would be installed at a primary data site and a single-processor gateway at a remote site.
In addition to asynchronous and synchronous replication, the NAS gateways offer another mirroring option-Mirror Write Consistency (MWC), or HACMP- XD. Available since March, MWC addresses the performance and data-loss issues associated with asynchronous and synchronous mirroring, respectively.
"It writes to the local copy and remote copy simultaneously but it waits to hear back from the remote site before signaling that the I/O is complete," explains Vaughn. "That means it's faster than synchronous replication but still provides no data loss."
"What I like about the product is that you can run HACMP XD on the NAS gateway to replicate from one NAS gateway to another," says Dianne McAdam, a senior analyst and partner at the Data Mobility Group consulting firm.
The NAS Gateway 500 supports IBM disk arrays (e.g., TotalStorage Enterprise Storage Server and FAStT) and can be connected to non-IBM disk arrays using IBM's TotalStorage SAN Volume Controller (SVC). However, with a starting price of $60,000, the SVC may not be a realistic option for SMBs.
The NAS gateways also feature a new snapshot capability that allows users or administrators to recover files; an enhanced call-home capability, which allows administrators to make calls over a TCP/IP connection as well as via phone; support for link aggregation in clustered and non-clustered environments; and expanded Windows support (Windows 2003).