SQL server suddenly shut down

[#1]

Hi Friends,

We are using ECC 6 EHP 3 in Windows 2008r2 server with MSSQL 2005 .

And its running on 2 clusters .

Yesterday suddenly SAP was disconnected and DISP+WORK is went to gray status.for this we restarted the entire server .Now SAP is connecting and its working fine.

When ever we check for error log in sm21 Initialization DB-Connect Failed, Return Code 000256.

I want to know some information about this error.

At what time we will get this error.

What is the reason for this error .

how to fix this error.

As per my knowledge one of my friend try to change the password for SID user in MSSQL management studio. that time SAP is running.

Can any one help to find the reason for this error and let me know the effect of changing the SID password from SQL management studio while SAP application running time.

Please let me know any farther information required. 

[Matt_Fraser]

If by the SID user you mean the schema user (with sid in lowercase), then it shouldn't have mattered if the password changed.  This isn't a Java or dual-stack system, is it?  ABAP-only?  Is your SQL Server authentication set to "Windows-only?"

Is there any more information you can provide from the SM21 system log?  Also, look in the developer traces for the work processes for related errors at the same time.

Regards,

Matt