6.5. Creating the cluster.ccs File

Creating the cluster.ccs file consists of specifying the following parameters:

• Cluster name

• Each node that runs LOCK_GULM server

• Optional parameters

	Note
	Because of quorum requirements, the number of lock servers allowed in a GFS cluster can be 1, 3, 4, or 5. Any other number of lock servers — that is, 0, 2, or more than 5 — is not supported.

	Note
	Two optional cluster.ccs parameters, heartbeat_rate and allowed_misses, are included in this procedure for configuring sub-second node failure detection. For a description of other optional parameters, refer to the lock_gulmd(5) man page.

To create the cluster.ccs file, follow these steps:

1. Create a new file named cluster.ccs using the file structure shown in Figure 6-1. Refer to Table 6-1 for syntax description.

2. Specify ClusterName (for example, alpha). Refer to Example 6-1.

3. Specify each node (NodeName) that runs LOCK_GULM server (for example, n01, n02, and n03). Refer to Example 6-1.

4. (Optional) For the heartbeat rate (heartbeat_rate =), specify Seconds. Refer to Example 6-1.

   The Seconds parameter in combination with the allowed_misses Number parameter specifies the amount of time for node failure detection as follows:

   Seconds x (Number+1) = Time (in seconds)

5. (Optional) For the allowed consecutively missed heartbeats (allowed_misses =), specify Number. Refer to Example 6-1.

6. Save the cluster.ccs file.

cluster { 
	  name = "ClusterName" 
	  lock_gulm { 
	      servers = ["NodeName",..., "NodeName"]
              heartbeat_rate = Seconds  <-- Optional 
              allowed_misses = Number   <-- Optional
          } 
}

cluster { 
         name = "alpha" 
         lock_gulm { 
             servers = ["n01", "n02", "n03"] 
             heartbeat_rate = 0.3
             allowed_misses = 1
         } 
}