News

Update: Stratus Touts Uptime Achievement

• By Scott Bekker
• August 07, 2003

Stratus Technologies, maker of fault-tolerant Windows 2000 servers, is claiming its internal monitoring of more than 1,200 live customer units approached six nines of availability over the last six months. If true, the mark would signal an impressive level of scalability for the systems, which are based on industry-standard server components and Windows.

The 99.9998 percent uptime that Stratus says its systems achieved over the last six months translates to less than a minute of unplanned downtime for a server running 24x7 for one year. By comparison, reliable estimates for the uptime of Windows-based clusters are in the 99.9 percent uptime range -- about 8.5 hours of unplanned downtime over a year of non-stop operation.

Stratus guarantees high-end levels of uptime on servers running off-the-shelf server versions of Windows 2000 by providing hardened drivers and redundant hardware in its systems. Each functional processor in the one- to four-way SMP systems has another processor executing the exact same instructions. Memory is also mirrored in the Stratus servers. When a memory card or a processor fails, the redundant unit carries on the work, resulting in no transactions being lost and no downtime. An administrator can later replace the card or processor without shutting down the system.

In its announcement this week, Stratus did not report the amount of planned downtime for its systems. The major factor that would result in planned downtime would be the service pack and hotfix update cycle, which takes time and requires a reboot for any server. One bug fix in the recent Windows 2000 Service Pack 4, for example, addressed a problem specific to Stratus servers.

The Stratus uptime meter tracks uptime on servers that Stratus monitors remotely for customers as part of a service package. More than 80 percent of Stratus customers are covered by a service contract.