Features - Enterprise Data Insights:

CISCO ROUTER A WORKGROUP WORKHORSE
By Henry Baltazar for eWeek

It would be an exaggeration to say the fate of the iSCSI storage market rests on the Cisco SN 5428 Storage Router, but the success of this product will surely act as a barometer for the rest of the industry.

From both a symbolic and functional standpoint, Cisco Systems Inc's SN 5428 bridges the gap between the worlds of IP networking and Fibre Channel SANs (storage area networks) -- eliminating the need to implement costly Fibre Channel switches and host bus adapters and enabling organizations to break away from direct access storage.

The Cisco SN 5428 -- which has eight 2G-bps Fibre Channel ports that are used to hook in storage devices and two Gigabit Ethernet ports that act as uplinks to the IP network -- is suited primarily for small and midsize businesses.

This puts it a step below Nishan Systems Inc's enterprise-class IPS 3000-series switch, which has eight ports that can be either Gigabit Ethernet or Fibre Channel. (No plans for an enterprise version of the Cisco router have been announced.)

During eWeek Labs' tests using the Cisco SN 5428, we were able to easily link Fibre Channel-based RAID and solid-state disk units to test servers using standard Ethernet switches and adapters. Two Cisco SN 5428 routers can be linked for high availability.

Powered for Workgroups

From a performance viewpoint, the Cisco SN 5428 has enough pep to run most workgroup-class applications, but we would not recommend using it to replace a 2G-bps Fibre Channel switch for high-performance applications. In tests, the Cisco SN 5428 proved functional when used with e-mail servers and file servers, but our test environment did not max out the servers' capabilities.

To ensure that the storage system was never the bottleneck in our tests, we used Imperial Data's superfast SANaccelerator solid-state disk unit as our storage target.

Because we wanted to be sure that the Cisco SN 5428 was causing the latency in performance tests, we used Finisar Inc's SANQOS analysis tool to gauge the response times of the Fibre Channel and iSCSI networks.

We got the performance numbers by running Intel Corp's Iometer storage benchmark with a variety of test suites to find the maximum throughput per second and I/Os per second possible with each network.

Running a sequential read test with a relatively large (512KB) request size, we found that we could push up to 82MB per second of throughput to a single server going through the Cisco SN 5428.

In contrast, running the same test on a 2G-bps Fibre Channel SAN, we found that a single server could hit 164MB per second of throughput.

Although the 2G-bps Fibre Channel solution is far and away the winner here, the Cisco SN 5428's performance is impressive.

On the server side, the installation of Cisco's iSCSI driver was relatively painless. Once the driver was installed, we were able to log in to the iSCSI network and use storage resources. We used both Gigabit and Fast Ethernet cards, and we found that both worked reasonably well.

The Cisco SN 5428 doesn't have any Fibre Channel zoning capabilities, but the management and security of LUNs (logical unit numbers) is controlled by ACLs (access control lists) managed by the storage router.

Because Fibre Channel zoning won't be available in the near future, IT managers who want to install the Cisco SN 5428 in an existing SAN should be sure to implement Fibre Channel management tools that will ensure that LUNs reserved for the iSCSI SAN aren't accidentally written over by Fibre Channel hosts.

The ACLs identify LUNs by their worldwide names and hosts by IP addresses. After creating profiles for each of our test servers, it was relatively easy to assign storage to them.

When using the Cisco SN 5428 for long-range data mirroring over public data lines, virtual private networks should be used to maintain the security of the data transferred. In tests, we could set up functional SAN links even in older, Fast Ethernet environments. Of course, performance was nowhere near as usable as on the Gigabit Ethernet side.

To ensure maximum performance, we recommend creating separate virtual LANs for iSCSI traffic and implementing quality-of-service tools to ensure that mission-critical servers are not starved for storage resources.

We were able to manage the Cisco SN 5428 using either the command-line interface or a Web-based management tool. Both methods were fairly straightforward.

Senior Analyst Henry Baltazar is at henry_baltazar@ziffdavis.com.

Executive Summary: Cisco SN 5428 Storage Router

• Usability Excellent
• Capability Excellent
• Performance Fair
• Interoperability Good
• Manageability Good
• Scalability Good
• Security Good

Cisco's SN 5428 Storage Router allows IT managers to share consolidated Fibre Channel storage over standard IP networks. Although we don't expect to see the Cisco SN 5428 replacing high-end Fibre Channel switches (nor should it), the router will extend SAN benefits to low-end and midrange servers and/or to companies that can't afford a Fibre Channel SAN.

Cost Analysis

The implementation and acquisition cost of a single Cisco SN 5428, $11,995, is fairly trivial when compared with the combined cost of buying Fibre Channel networking equipment (switches and HBAs). Because the Cisco SN 5428 builds on IP networks, IT managers will be able to concentrate financial resources over the long haul.

(+) Relatively low cost; solid management and security; high-availability option.

(-) Lacks Fibre Channel management capabilities such as zoning; performance not suitable for high-end applications.

Contact: www.cisco.com.