Ramdisk Plus Cluster-Ramdisk

How to Implement the tempdb Solution on a Machine that Is Part of a Cluster

Preliminary considerations on installing Ramdisk for Microsoft Cluster Servers:

• Examine the size of the tempdb file and the amount of available free memory. If the tempdb file is 100 MB or less, a RAM disk is unlikely to improve performance. If the tempdb file is greater than available physical memory, add more RAM to the system.



• Determine which unassigned drive letter to reserve for the RAM disk.



• Determine which NTFS volume on a cluster-shared physical disk will host the folder that will serve as a mount point for the RAM disk, and the folder's name.



• Consider the impact of reallocating system memory to the RAM disk. Sufficient memory resources must be available for SQL and other processes.



• On a production machine, determine a convenient time when SQL Server can be stopped. SQL must be stopped to configure cluster dependencies, change the tempdb path, and, possibly, to reduce its memory allocation limit.

1. Install RamDisk or RamDisk Plus (version 8.0.3 or greater) on each cluster node. To install successfully, the cluster service must be running on the node.


2. Stop SQL Server.
   
   
3. Add a local RAM disk to each cluster node. (Use the same parameters on each node.)
   
   1. Select a size large enough to contain the tempdb file.
   
   
   2. Select an appropriate drive letter.
   
   
   3. Select "NTFS" file system, without compression.
      With RamDisk Plus:
   
   
   4. Use the default image location.
   
   
   5. Do not enable "Save at system shutdown" or "Reserve space for full disk".
   
   
   
4. Create a folder on a shared cluster disk to serve as the mount point for the local RAM disk.



5. Create a RAM Disk cluster resource.


1. On the first page of the "New Resource" wizard, enter the name of the new RAM Disk resource and select the cluster group to which it will belong.
   
   
2. Navigate through the wizard, setting the appropriate dependencies, etc. Be sure to set the RAM Disk resource as dependent on the physical disk resource which contains the folder to be used as a mount point.



3. On the last wizard page "RAM Disk Cluster Resource Parameters", enter the fully-qualified path to the folder previously created in step 4. The path must include a trailing backslash (\).



6. Test the RAM Disk cluster resource. (If necessary, create a test group and place the physical disk resource and RAM Disk resource in the group. Once complete, place the resources in their original group.)


1. Bring the RAM Disk cluster resource online.


2. Move the group containing the RAM Disk cluster resource to another node.


3. If both these actions are successful, continue with installation. Otherwise, troubleshoot the problem.



7. Configure SQL Server to work with the RAM Disk cluster resource.
   
   1. Configure the SQL Server cluster application to be dependent on the RAM Disk cluster resource.
      
   2. Configure SQL Server to place its temporary data in the folder which serves as the RAM disk's mount point.
   
   
   3. If necessary, reduce the SQL Server's system memory allocation limit..
   
   
   
8. Start SQL Server.



9. Test SQL Server with its RAM Disk cluster resource.


1. Move the SQL group, while SQL is running, to another node.


2. Restart a node that is available to host SQL. After restarting, move SQL, while running, to that node.


3. If both these actions are successful, the installation is complete. Otherwise, troubleshoot the problem.