By Dave Simpson
Despite the fact that the technology will not be available from major vendors until next year, end users are surprisingly interested in running storage applications in fabrics, as opposed to hosts or storage subsystems. In a recent InfoStor QuickVote reader survey, 38% of the respondents said they would prefer to run their storage applications on fabric switches (including directors), while 41% prefer disk arrays and 21% voted for host-based applications (see chart).
In another QuickVote reader survey, fabric-based applications drew greater interest than other emerging storage technologies such as iSCSI, NAS-SAN convergence, SAN extension over WANs, and InfiniBand (see chart).
But it may be 2004 before you'll be able to fire up selected applications on fabric platforms. For example, a variety of software vendors are in various stages of porting their applications to Brocade's SilkWorm Fabric Application Platform (which it acquired from Rhapsody Networks), but that platform won't be available from Brocade OEMs until at least year-end. (Hewlett-Packard is the only Brocade OEM that has committed to that delivery timeframe.)
Vendors that have announced that they are porting applications to Brocade's Fabric Application Platform include Alacritus, Comm- Vault, EMC, FalconStor, HP, Incipient, InterSAN, Kashya (see related story in this issue, p. 10), StoreAge, Topio, and Veritas.
Tom Buiocchi, vice president of marketing at Brocade, expects about half of those companies to complete their ports by the time the platform is available.
A number of vendors, including EMC and Veritas, have also announced intentions of porting their software to Cisco's MDS 9000 family of fabric switches and directors, with some applications due by year-end.
Veritas, for example, plans to have a port of its Volume Manager (VM) software available for Cisco's MDS switches within the next two months. A version of VM for Brocade's Fabric Application Platform is due "in the second half of next year," according to Jose Iglesias, vice president of integrated products at Veritas. The fabric-based version of VM will be called Network Volume Manager (NVM).
It's important to note that Veritas has so far announced that it will port only VM to fabric platforms; the rest of Veritas' applications will continue to run on hosts, although the company will provide hooks between NVM and applications such as SANPoint Control.
In addition, a number of start-ups have introduced—or will within the next month or two—switches designed to host storage applications. Examples include MaXXan Systems (see "MaXXan enters storage switch market," InfoStor, March 2003, p. 10) and Sanera Systems (see "Sanera director aimed at high-end NAS," InfoStor, May 2003, p. 14). Maranti Networks, another start-up, is expected to ship an intelligent switch within a month or two.
Brocade's Buiocchi contends that any application that involves data movement is a likely candidate for fabric-based intelligence. That includes applications such as replication, mirroring, snapshots, volume management, and backup/restore. Obviously, he says, it does not make sense to run applications such as file systems and caching in the fabric.
According to proponents, the potential advantages of fabric-based applications include
- Centralized and consolidated storage management and provisioning;
- The ability to more easily (and inexpensively) replicate data between heterogeneous disk arrays; and
- Lower operation and management costs.
What remains to be seen is how software vendors will price their fabric-based applications and whether end users will actually realize any overall cost savings from moving applications into storage networks. Most likely, vendors will price their software based on capacity, rather than on a per-node basis.
Veritas, for example, has not determined a pricing model for the fabric version of its Volume Manager software, according to Iglesias.
"The capital cost of fabric-based software may not be less than host-based or array-based software, but because of reduced maintenance and management costs it should lead to reduced overall costs," claims Brocade's Buiocchi.
Fabric-based applications are expected to be phased in over time.
Running storage applications in the fabric is not new. Vendors such as DataCore and FalconStor have for years sold "SAN appliances" (virtualization engines and applications). However, those appliances run storage applications on off-the-shelf servers, as opposed to "purpose-built" platforms.
A new entrant in the market for fabric-based applications is Troika Networks, formerly a manufacturer of high-end, multi-protocol host bus adapters (HBAs). (The company has since exited the HBA market.) Troika's Network Storage Services (NSS) Platform is due in the fourth quarter with storage applications from a number of vendors. For example, Incipient, StoreAge, and Topio are porting applications to Troika's platform.
According to Bill Terrell, Troika's president and CEO, the NSS platform is positioned as an alternative to SAN appliances and intelligent switches that can host applications. The Linux-based platform is a purpose-built device that includes 16 Fibre Channel ports and Troika's ASICs. (The company claims wire-speed performance, and 500,000 I/Os per second.)
Versus SAN appliances built on off-the-shelf servers, Troika claims advantages in the areas of performance and reliability, at equal or slightly higher prices. Versus switches and directors, the company claims lower cost and easier deployment and management. (Pricing has not yet been determined.)
Applications expected to ship with Troika's system include volume management, storage virtualization, replication, snapshots, mirroring, and data-protection applications such as backup/recovery and continuous backup.