---
title: "Check disk IO Subsystem for read retry problems - Policy-Based Management"
description: This rule checks the event log for SQL Server error message 825, which indicates SQL Server was unable to read data from the disk on the first try. 
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: 
  - "Best Practices [Database Engine]"
ms.assetid: cedf4097-5b73-4964-9935-74a101847019
author: VanMSFT
ms.author: vanto
---
# Check Disk Input-Output Subsystem for Read Retry Problems
[!INCLUDE[appliesto-ss-xxxx-xxxx-xxx-md](../../includes/appliesto-ss-xxxx-xxxx-xxx-md.md)]
  This rule checks the event log for [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] error message 825. This message indicates that [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] was unable to read data from the disk on the first try. This message indicates a major problem with the disk I/O subsystem. This message does not currently indicate a [!INCLUDE[ssNoVersion](../../includes/ssnoversion-md.md)] problem. However, the disk problem could cause data loss or database corruption if it is not resolved.  
  
## Best Practices Recommendations  
 The following actions might help you discover and resolve the underlying hardware problem:  
  
-   Review the error log and the variable text in this message for clues that explain the problem.  
  
-   Check the disk system. The problem could be related to the disks, the disk controllers, array cards, or disk drivers.  
  
-   Contact the disk manufacturer for the latest utilities for checking the status of the disk system.  
  
-   Contact the disk manufacturer for the latest driver updates.  
  
## For More Information  
 [MSSQLSERVER_825](../errors-events/mssqlserver-825-database-engine-error.md)  
  
 [SQL Server I/O Basics, Chapter 2](/previous-versions/sql/sql-server-2005/administrator/cc917726(v=technet.10))