| title | Check disk IO subsystem for IO delay problems | |
|---|---|---|
| description | Learn how to enable a policy to check the disk IO subsystem for IO delay problems by checking the event log for error message 833 for Policy-Based Management with SQL Server. | |
| ms.custom | seo-lt-2019 | |
| ms.date | 03/14/2017 | |
| ms.prod | sql | |
| ms.prod_service | database-engine | |
| ms.reviewer | ||
| ms.technology | security | |
| ms.topic | conceptual | |
| helpviewer_keywords |
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| ms.assetid | 23863340-d8e0-48d6-928b-462745885d37 | |
| author | VanMSFT | |
| ms.author | vanto |
[!INCLUDEappliesto-ss-xxxx-xxxx-xxx-md] This rule checks the event log for error message 833. This message indicates that [!INCLUDEssNoVersion] has issued a read or write request from disk, and that the request has taken longer than 15 seconds to return. This error is reported by [!INCLUDEssNoVersion] and indicates a problem with the disk I/O subsystem. Delays this long can severely damage the performance of your [!INCLUDEssNoVersion] environment.
Troubleshoot this error by examining the system event log for hardware-related error messages. Also, examine hardware-specific logs if they are available.
Use Performance Monitor to examine the following counters:
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Average Disk Sec/Transfer
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Average Disk Queue Length
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Current Disk Queue Length
For example, the Average Disk Sec/Transfer time on a computer that is running [!INCLUDEssNoVersion] is typically less than 15 milliseconds. If the Average Disk Sec/Transfer value increases, this indicates that the disk I/O subsystem is not optimally keeping up with the I/O demand.