Burning in the System


Before you move a system into common use, you should "burn it in." This means that you should stress the server. It is not unusual for a server to work in production for months or years with a hardware problem that existed at the time of the deployment of the server. Many of these failures will not show up when the server is under a light load but will become immediately evident when the server is pushed hard.

Several years ago, using SQL Server 6.5, I would get a 605 corruption error. This would cause me to have to restore the database that had the error. When the restore was complete, I'd run my DBCCs and get a clean result. Within a week I'd get another 605 error and have to stay up late in the evening restoring the same server. After getting really upset at this recurring problem, I discovered that I had a disk controller failing only near 100-percent utilization. This is exactly the kind of problem that burning in your system is intended to expose prior to production. It's much easier to fix hardware before it goes live.

A second use of some of these tools is to compare the IO throughput of your new system to your requirements or to the performance of an older system. While many tools are available, you can get two of them from Microsoft. One tool is called SQLIO, which is a disk subsystem benchmark tool. Microsoft provides this with no warranty and no support, but it is still a good tool to use. It is available from www.microsoft.com/downloads; search for SQLIO.

The second tool is SQLIOStress. You can download it from http://support.microsoft.com/default.aspx?scid=kb;en-us;231619 or search for SQLIOStress in Microsoft downloads. This tool simulates the IO patterns of SQL Server, although it does so directly, without using your SQL install. It simulates write-ahead logging, page inserts and splits, checkpoints, read-ahead, sorts, hashes, backup scans, and many other scenarios. In addition, it does over 150 verification and validation checks. I would not put a server into use without using this tool. When you use this tool, you must identify a data and log file. Be sure you use the same data and log file locations you will be using when you create your databases, so you will be testing the right areas of your I/O subsystem.

Neither of these tools depends on SQL Server being installed, so you can do this burn-in either before or after the SQL install.



Professional SQL Server 2005 Administration
Professional SQL Server 2005 Administration (Wrox Professional Guides)
ISBN: 0470055200
EAN: 2147483647
Year: 2004
Pages: 193

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