By Dave Simpson
Dell Computer has finally introduced its long-awaited SAN appliance, a trip that began with the ill-fated acquisition of ConvergeNet and ended in a partnership with StorageApps. Earlier this month, Dell announced that it will resell StorageApps' SAN appliance software bundled with its PowerEdge 6450 NT servers.
SAN appliances promise to simplify building, managing, and moving data in storage area networks by creating a virtual storage pool. (For more information about SAN appliances, see InfoStor, July 2000, p. 1.)
Unlike independent SAN appliance vendors' products, Dell's PowerVault 530F works only with Dell's storage devices (it is not qualified with storage subsystems from other vendors) and servers (although the appliance has been qualified with a limited number of Com-paq servers).
Dell has formed a custom solutions group to deal with truly heterogeneous environments, according to Bruce Kornfeld, director of PowerVault product marketing at Dell.
Architecturally, the 530F uses an in-band technique, in which the appliance sits in the data path between the servers and storage devices. One potential disadvantage of this approach, in single-appliance configurations, is that the appliance represents a point of failure. As such, Dell recommends redundant appliances with failover software.
Another potential disadvantage of the in-band technique is performance degra dation. However, Kornfeld says that performance depends on a number of factors, including the total capacity being managed by the SAN appliance.
One key advantage of the in-band approach is that, unlike out-of-band SAN appliances, it does not require special software on all the SAN-attached servers.
In addition to StorageApps and Dell, other SAN appliance vendors include Compaq, DataCore Software, DataDirect Networks, StoreAge, Veritas Software, and Vicom. DataCore's "storage domain manager" software is resold in bundled configurations by vendors such as Gadzoox Networks and TrueSAN Networks.
According to Steve Duplessie, senior analyst with the Enterprise Storage Group, a consulting firm in Milford, MA, StorageApps may have an early advantage over other SAN appliance vendors. For example, in addition to virtualization, Duplessie points out, StorageApps has added a number of storage-centric applications, such as mirroring (synchronous or asynchronous, remote, and three-way), point-in-time snapshot copies, and LUN masking/mapping (see "StorageApps enters SAN appliance market," InfoStor, August 2000, p. 11). However, that advantage may prove short-lived because other SAN appliance vendors are expected to add those capabilities over the next few months.
Pricing for Dell's PowerVault 530F ranges from $38,000 to $43,000, or on average about $80,000 for a dual-appliance configuration, according to Kornfeld.
Separately, Dell entered the low-end network-attached storage (NAS) market via a reseller deal with Quantum. Dell plans to sell Quantum's Snap Server for $3,000 in a 120GB configuration. (For mid-range and high-end applications, Dell resells Network Appliance's NAS filers.)
Dell's PowerVault 705N NAS appliance is compatible with all versions of Win-dows, as well as NetWare, Solaris, Red Hat Linux, SCO, and Macintosh operating systems. The 705N can be configured for RAID levels 0, 1, and 5.
Director of PowerVault product marketing,