INF: Compaq IDA-2 Controller and SQL Data Corruption

ID: Q98630

The information in this article applies to:

Microsoft SQL Server for OS/2, version 4.2
Microsoft SQL Server version 4.2x

SUMMARY

There is a known problem with the Compaq IDA-2 disk controller that can cause SQL Server data corruption.

Compaq has confirmed that under high levels of stress, the Compaq IDA-2 controller may cause data corruption due to a firmware problem related to write-caching. The symptom is typically a 605 error, often on syslogs:

Attempt to fetch logical page <page> in database <db name> belongs to object <object name> not to object <object name>

The suggested solution is to run Compaq IDA-2 firmware level 2.60 or later. An interim solution prior to updating is to turn off IDA-2 write-caching.

This firmware update is available in two versions:

It can be downloaded from Compaq's web page at www.compaq.com. The upgrade changes are saved in the reserved area of each hard disk attached to the controller. In the event that it cannot be read from one disk, it is read from the next disk. If it cannot be read from any of the attached disks, the controller will revert to the previous version and the corruption may return.

Upon replacement of any failed drive, Compaq recommends that the upgrade be performed again so that the new firmware is recorded on the new drive, thus preventing reversion to the previous state.

The firmware update is also available as a new firmware chip from Compaq or a Compaq dealer.

A separate problem was found with the Compaq IDA-E expansion controller. This controller isn't as widely used, and is for attaching an expansion chassis of hard disk drives to a SystemPro. In this case, firmware version 1.18 or later is required.

The Compaq Diagnostic disk has a program called "inspect" that can be used to determine what firmware version the system is running.

MORE INFORMATION

With the above problem corrected, the Compaq IDA-2 is the only write- caching controller currently known that potentially will not jeopardize SQL Server data integrity. Compaq believes it has eliminated all known causes of cache-induced problems in the IDA-2 design. It has on-board battery backup, mirrored RAM, and they intercept in hardware all causes of bus and controller reset, including the reboot switch.

Additional query words: write caching Windows NT


Keywords          : kb3rdparty SSrvServer SSrvWinNT 
Version           : 4.2 | 4.2 4.21 4.21a
Platform          : OS/2 WINDOWS 
Issue type        :

Last Reviewed: March 16, 1999