Beginning in SQL Server 2012, you can view SQL Server log files from a local or remote instance of SQL Server when the target instance is offline or cannot start.
You can access the offline log files from Registered Servers, or programmatically through WMI and WQL (WMI Query Language) queries.
You can also use these methods to connect to an instance that is online, but for some reason, you cannot connect through a SQL Server connection.
Before you Begin
To connect to offline log files, an instance of SQL Server must be installed on the computer that you are using to view the offline log files, and on the computer where the log files that you want to view are located. If an instance of SQL Server is installed on both computers, you can view offline files for instances of SQL Server, and for instances that are running earlier versions of SQL Server on either computer.
If you are using Registered Servers, the instance that you want to connect to must be registered under Local Server Groups or under Central Management Servers. (The instance can be registered on its own or be a member of a server group.) For more information about how to add an instance of SQL Server to Registered Servers, see the following topics:
For more information about how to view offline log files programmatically through WMI and WQL queries, see the following topics:
SqlErrorLogEvent Class (This topic shows how to retrieve values for logged events in a specified log file.)
SqlErrorLogFile Class (This topic shows how to retrieve information about all SQL Server log files on a specified instance of SQL Server.)
To connect to an offline log file, you must have the following permissions on both the local and remote computers:
Read access to the Root\Microsoft\SqlServer\ComputerManagement12 WMI namespace. By default, everyone has read access through the Enable Account permission. For more information, see the "To verify WMI permissions" procedure later in this section.
Read permission to the folder that contains the error log files. By default the error log files are located in the following path (where <Drive> represents the drive where you installed SQL Server and <InstanceName> is the name of the instance of SQL Server):
<Drive>:\Program Files\Microsoft SQL Server\MSSQL13.<InstanceName>\MSSQL\Log
To verify WMI namespace security settings, you can use the WMI Control snap-in.
To verify WMI permissions
Open the WMI Control snap-in. To do this, do either of the following, depending on the operating system:
Click Start, type wmimgmt.msc in the Start Search box, and then press ENTER.
Click Start, click Run, type wmimgmt.msc, and then press ENTER.
By default, the WMI Control snap-in manages the local computer.
If you want to connect to a remote computer, follow these steps:
Right-click WMI Control (Local), and then click Connect to another computer.
In the Change managed computer dialog box, click Another computer.
Enter the remote computer name, and then click OK.
Right-click WMI Control (Local) or WMI Control (RemoteComputerName), and then click Properties.
In the WMI Control Properties dialog box, click the Security tab.
In the namespace tree, locate and then click the following namespace:
Make sure that the account that will be used has the Enable Account permission. This permission allows Read access to WMI objects.
View Log Files
The following procedure shows how to view offline log files through Registered Servers. The procedure assumes the following:
The instance of SQL Server that you want to connect to is already registered in Registered Servers.
To view log files for instances that are offline
If you want to view offline log files on a local instance, make sure that you start SQL Server Management Studio with elevated permissions. To do this, when you start Management Studio, right-click SQL Server Management Studio, and then click Run as administrator.
In SQL Server Management Studio, on the View menu, click Registered Servers.
In the console tree, locate the instance on which you want to view the offline files.
Do one of the following:
If the instance is under Local Server Groups, expand Local Server Groups, expand the server group (if the instance is a member of a group), right-click the instance, and then click View SQL Server Log.
If the instance is the Central Management Server itself, expand Central Management Servers, right-click the instance, point to Central Management Server Actions, and then click View SQL Server Log.
If the instance is under Central Management Servers, expand Central Management Servers, expand the Central Management Server, right-click the instance (or expand a server group and right-click the instance), and then click View SQL Server Log.
If you are connecting to a local instance, the connection is made using the current user credentials.
If you are connecting to a remote instance, in the Log File Viewer - Connect As dialog box, do either of the following:
To connect as the current user, make sure that the Connect as another user check box is cleared, and then click OK.
To connect as another user, select the Connect as another user check box, and then click Set User. When you are prompted, enter the user credentials (with the user name in the format domain_name\user_name), click OK, and then click OK again to connect.
If the log files take too long to load, you can click Stop on the Log File Viewer toolbar.