Cannot connect to the configuration database in SharePoint 2010

Yesterday I ran into one issue Cannot connect to the configuration database in SharePoint 2010.

Verified all the services in the App server.
Even unable to open the Central Admin Page also.

Issue:

Error from the Browser : Cannot connect to the configuration database.

Error from EventViewer:

 

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server).

Resolution:

I.  Verified that the SQL database service is running in the Sqlserver

1. Click Start, point to Programs, point to Administrative Tools, and then click Services.
2. In the list of services, locate the MSSQLSERVER service. This service may also be listed as MSSQL$SHAREPOINT.
3. Note the value of the Status column. If the Status column lists Started, the database server is running. If the Status column is empty, the database server is not running.
   
   To start the database server, right-click the MSSQLSERVER service, and then click Start

II.  verify that the account that is used by the application pool is the account that has the required permissions to the SQL Server database.I.e. Please verify these two accounts Domain\AdminAccnt and Domain\AdminAccntApppool have     enough permission level to access the SharePoint content Databases. 

Root Cause :  A disk resource failure on the Sql Box and Clustered disk resource was in failed state.

Reference:http://support.microsoft.com/kb/823287/en-us