看看就明白了（from msdn）
CAUSE
When Windows I/O operations fail due to insufficient system resources or because of insufficient working set quota, SQL Server reports error 823 or error 8966 without attempting a retry. These conditions can be reported by the operating system on a normal system, due to the current workload at that instance. If you retry the operation later it might work because of changing loads and system resources availability. STATUS
Microsoft has confirmed this to be a problem in SQL Server version 7.0. This problem has been corrected in U.S. Service Pack 3 for Microsoft SQL Server version 7.0. For information about how to download and install the latest SQL Server Service Pack, see the following Microsoft Web site: http://support.microsoft.com/view/dev.asp?ID=hl&pg=sql.asp
For more information, contact your primary support provider.
CAUSE
When Windows I/O operations fail due to insufficient system resources or because of insufficient working set quota, SQL Server reports error 823 or error 8966 without attempting a retry. These conditions can be reported by the operating system on a normal system, due to the current workload at that instance. If you retry the operation later it might work because of changing loads and system resources availability. STATUS
Microsoft has confirmed this to be a problem in SQL Server version 7.0. This problem has been corrected in U.S. Service Pack 3 for Microsoft SQL Server version 7.0. For information about how to download and install the latest SQL Server Service Pack, see the following Microsoft Web site: http://support.microsoft.com/view/dev.asp?ID=hl&pg=sql.asp
For more information, contact your primary support provider.
CAUSE
When Windows I/O operations fail due to insufficient system resources or because of insufficient working set quota, SQL Server reports error 823 or error 8966 without attempting a retry. These conditions can be reported by the operating system on a normal system, due to the current workload at that instance. If you retry the operation later it might work because of changing loads and system resources availability. STATUS
Microsoft has confirmed this to be a problem in SQL Server version 7.0. This problem has been corrected in U.S. Service Pack 3 for Microsoft SQL Server version 7.0. For information about how to download and install the latest SQL Server Service Pack, see the following Microsoft Web site: http://support.microsoft.com/view/dev.asp?ID=hl&pg=sql.asp
For more information, contact your primary support provider.