By Dave Simpson
StorageApps Inc. is the latest entrant in the emerging market for so-called SAN appliances, sometimes referred to as storage domain managers. Formerly RAID Power Services Inc., StorageApps changed its name in February.
Other players in the SAN appliance market include Compaq, DataCore Software, DataDirect Networks, Dell, StoreAge, Veritas Software, and Vicom. Gadzoox Networks and TrueSAN Networks have also entered the market by bundling DataCore's SANsymphony software with Windows NT platforms. (For more information on SAN appliances and storage domain managers, see InfoStor, July, p. 1: "Appliances ease SAN implementation, management.")
Although competition is expected to heat up as user awareness of SAN appliances grows, StorageApps may have an advantage over its rivals, as least for now. "In addition to storage virtualization, StorageApps has also developed storage-centric applications to run on their appliance, like mirroring, snapshot, and instant imaging," says Steve Duplessie, senior analyst with Enterprise Storage Group, a consulting firm in Milford, MA. However, other SAN appliance vendors are expected to add similar capabilities over the next few months.
SANLink works with heterogeneous servers, and creates a virtual storage pool out of heterogeneous subsystems.
Duplessie also notes that StorageApps may have an edge because some of the company's executives were formerly end users. For example, a number of executives came from Morgan Stanley.
Vendors' approaches to SAN appliances vary widely, but they all promise end-user benefits in the areas of SAN implementation, upgrading, and manageability. In some cases, vendors promise performance improvements.
Unlike out-of-band SAN appliances, such as those from Compaq and StoreAge, StorageApps (and most of the other SAN appliance vendors) use an in-band technique (e.g., the appliance sits in the data path). Duplessie notes that there are potential advantages and disadvantages to both approaches. "The appliance could be a bottleneck if it's in-band," says Duplessie, "but one advantage is that the in-band approach doesn't require software on every host."
The requirement for running software driver code on every SAN-attached server is a prime drawback to the out-of-band approach, according to Duplessie. "On the positive side, however, with an out-of-band approach you potentially have unlimited scalability because the appliance is not in the data path," he adds.
Like other SAN appliances, StorageApps' SANLink provides storage virtualization by creating a storage "pool," and security features such as LUN masking across heterogeneous server platforms and storage subsystems. Unlike many other SAN appliances, SANLink also provides data mirroring (synchronous or asynchronous over Fibre Channel or IP) and point-in-time imaging (also referred to as snapshot capability).
Differing from SAN appliances such as DataCore's, StorageApps does not implement SAN caching. StorageApps president and COO Dan Petrozzo argues that caching is not required to boost performance: "The bottlenecks are at the HBA [host bus adapter] and disk drive level, and most disk arrays already have caching," Petrozzo contends.
SANLink is a bundle that includes a Windows NT server with QLogic HBAs, SAN.OS code that layers on NT, and SANSuite applications. The system uses Fibre Channel front-end connections, Fibre Channel or SCSI on the back end, and can use native IP for mirroring. StorageApps also provides services that include remote monitoring, installation, upgrading, and alerting. A one-year, 24x7 service is included in the SANLink bundle.
According to Petrozzo, future enhancements will include additional clustering features (via collaboration with Veritas), support for third-party backup, one-button data migration/mirroring, and support for network-attached storage (NAS).
A 32-port SANLink implementation is priced around $200,000. StorageApps is headquartered in Bridgewater, NJ: www.storageapps.com.
Enterprise Storage Group (www.enterprisestoragegroup.com) recently surveyed more than 200 end users about their view of storage area networks (SANs). Here are some of the results.
- 83% of user respondents said that lack of interoperability among various components is the most significant problem with SAN technology.
- 77% of SANs are implemented as homogeneous SAN "islands" (one type of operating system, switch, and storage array).
- 61% of users believe SAN technology is "very difficult" to implement.
- Only 16% of respondents think that SANs live up to their original promise. But 79% of those respondents think that this will improve over the next 24 months.