Using the Cluster Configuration (SCSI Only)

A P P E N D I X C

For the Sun StorEdge 3310 SCSI array, if you are using Win32, Sun StorEdge Configuration Service can monitor shared SCSI storage. This section covers the following topics:

Planning the Cluster Configuration

Cluster Configuration Requirements

To Set Up Cluster Configuration

A cluster configuration must be set up with the appropriate hardware first, and it also requires Windows 2000 or 2003 Server and Microsoft Cluster Server (MSCS) software.

If you are planning to set up a cluster configuration, make sure to read this chapter.

Planning the Cluster Configuration

Before you set up a cluster configuration, you need to determine what type of configuration you want because it can make a difference in how you configure the storage initially.

There are two main types of cluster configuration:

A hot standby server cluster where all of the LUNs belong to one of the two servers in the cluster. If the server owning the LUNs fails, the LUNs are moved to the second server, which has been idle to this point. A minimum of two LUNs are required in this configuration.

A load balanced cluster, where some LUNs are maintained on one server and some LUNs are maintained on the other server. Both servers process data at the same time, but they are processing I/O on different LUNs.

A minimum of three LUNs must be defined. This enables one small LUN to be established for quorum disk use and a large LUN to be used on each server in the cluster. The quorum disk maintains the cluster configuration data necessary to recover the cluster in the event of a server failure.

Cluster Configuration Requirements

When you are installing the MSCS software, identify the disk to be used for the quorum disk, which maintains cluster information.

In a cluster configuration, the program runs on only one server at a time, the server that has the quorum disk. If the server running with Sun StorEdge Configuration Service malfunctions, the Cluster Administrator automatically changes the first server’s disk load to the second server and start the services on that server.

In a two-server cluster configuration, the cluster itself, with its own IP address, becomes the managed server on the Managed Servers list. Add the cluster to the Managed Servers list as the last step in setting up the cluster.

To Set Up Cluster Configuration

Following is an overview of the steps needed to set up an array in a cluster configuration with two host servers.

1. Set up the servers:

a. Set up the two servers, each with a PCI bus and a boot disk that is not a part of the shared SCSI storage.

b. Install a host adapter card such as Ultra-Wide, differential host adapter, in each server and set a unique SI ID for each host adapter on the shared SCSI bus.

c. Install two network adapter cards on each server.

d. Install the latest Windows updates on the boot disk of each server.

2. Install the dual active-active storage subsystem and connect it to both host adapters.

Refer to the supplied documentation for installation steps.

3. Install the agent on each server:

a. Stop the services on one server before installing it on the other server.

b. Ensure that the service is running on a server that has access to a host LUN mapped on logical drive assigned to primary controller.

c. See the appropriate installation chapter for specific steps for installing the agent.

After installing the agent, you do not need to reboot. However, once the agent is installed, be sure to stop the services on one of the servers.

Note - In the next few steps, you will work with one server only as an example.

4. Install the console software.

You can install the console on one of the servers or on any computer on the network where the servers reside. The program enables you to configure and monitor the array remotely. See the appropriate installation chapter for detailed steps.

5. Add the server that has started the services to the console’s Managed Servers list (see To Add Servers).

Be sure to select Auto Discovery and add the ssmon password.

6. Use the console software to verify and configure the storage on the active server and then reboot that server.

Your storage array might already be preconfigured on the dual active-active storage subsystem. You need to look at the configuration in the tree view to determine whether this is the case.

If the storage is not configured or you want to change the configuration, configure all of the LUNs on one server. Later, after the MSCS software is installed, you can allocate the storage between the servers with Cluster Administrator.

7. Use Computer Management to create partitions and format the LUNs on the active server:

a. If necessary, reassign drive letters for the disks.

Note that partitions must be formatted with NTFS.

Windows sees the LUNs on the dual active-active controllers as being on both servers in the cluster. You can create partitions and logical drives on only one server. Later, after MSCS is installed, you can use the Cluster Administrator to apportion the storage between the two servers.

The drive letters for the shared SCSI storage for the two servers must be the same. If there is an additional CD-ROM drive or external hard disk on one server and not on the other, you might need to reassign the drive letters for the shared storage. After this step, check them on the other server to make sure they are the same.

b. Write down the drive letters assigned to the shared storage.

8. Access the second server, start Computer Management and make sure that the second server has the same drive letters as the first.

If it does not, reassign the drive letters so that they are consistent on both servers.

9. Shut down the second server.

10. Install the MSCS software on the first server and reboot.

11. Start Cluster Administrator and make sure that it can see the cluster.

12. Access the second server, install MSCS on that server by joining it to the first, and reboot.

13. Reboot the second server and verify in Cluster Administrator that both servers are included in the cluster.

14. Adjust the disk groups in the Cluster Administrator.

Make sure that the quorum disk and the other disks, if any, are together in one disk group under the first server where you originally configured the storage. Refer to the MSCS documentation for details to perform this step.

Note - Once you put the two LUNs in the same disk group, you have an empty disk group that you can delete.

15. Add the services to the group that has the quorum disk on the first server:

a. On both servers, stop each of the three services, Configuration Service Startup, Configuration Service Monitor, and Configuration Service Server, and set them to manual.

b. Use Cluster Administrator to install each service as a resource to the group that has the quorum disk.

For each service, enter it in the following order and type its name in the format indicated (with the two words run together). After each service is installed, bring the service online to start it on the active server.

Enter the services as generic services. You are asked to indicate the dependencies for each resource. The dependencies in the group are as follows:

Disk associated with the quorum disk

Other disk, if any to be added to this group

Configuration ServiceStartup

Configuration ServiceMonitor

Configuration ServiceServer

Configuration ServiceStartup is dependent on the two disks that are already in the group. Configuration ServiceMonitor is dependent on Configuration Service Startup, and Configuration ServiceServer is dependent on Configuration Service Monitor.

16. For the two cluster servers to be displayed as one icon under the cluster IP address, edit CLUSTER.TXT.

The file is located in the same directory as the console files. It is on the system disk of the computer where the console is installed. If Drive C is the system disk, the path is:

C:\Program Files\Sun\sscs

The following text shows the contents of the file:

#Edit this file to map the cluster IP address to several
#servers constituting the cluster.
#The format of the entry is:
#<Cluster IP Address>=<server1 IP Address>:<server2 IP Address>
#The IP address must be in dot form.
#Example: If the cluster IP address is 151.239.130.70 and the
#IP addresses of individual servers are 151.239.130.71 and
#151.239.130.72,the entry would be:
# 151.239.130.70=151.239.130.71:151.239.130.72
#
#IMPORTANT NOTE:
#Use only the Cluster IP address to configure a cluster
#server on the Configuration Service console.
#
#151.239.130.70=151.239.130.71:151.239.130.72

17. Edit the last line of the file to insert the IP address of the cluster and then the IP addresses of the two servers that make up the cluster by removing the number symbol (#).

18. Start the console and remove the first server from the Managed Servers list, and add the cluster as a server to the list.

19. Access the Server List Setup function. See To Add Servers.

Be sure to select Auto Discovery and add the ssmon password. If you type in the cluster name, the program supplies the IP address if your network has DNS.

At this point, the cluster configuration is properly configured to work with the program. If the server that has the services running on it malfunctions, its disk groups are transferred to the second server and the Cluster Administrator automatically starts the services on that server.

Note - When one server fails, it can take as long as 15 minutes for the cluster icon in the console to turn from purple to gray and perhaps another 10 minutes before it goes back to purple again.

If you want to have a load balanced configuration with some of the storage running on the other server, you need to use the Cluster Administrator to move one or more disk groups to the other server.