Creating a disaster recovery RDQM

We use the crtmqm command to create a replicated data queue manager (RDQM) to act as a primary or a secondary in a disaster recovery configuration.

About this task

We can create a replicated data queue manager (RDQM) as a user in the mqm group if the user can use sudo. Otherwise you must create the RDQM as root.

You must create a primary RDQM DR queue manager on one node. Then you must create a secondary instance of the same queue manager on another node. The primary and secondary instances must have the same name and be allocated the same amount of storage.

Procedure

• To create a primary DR RDQM:
  1. Enter the following command:

     crtmqm -rr p [-rt (a | s)] -rl Local_IP -ri Recovery_IP -rn Recovery_Name -rp Port [other_crtmqm_options] [-fs size] QMname

     where:

     -rr p

     Specifies that you are creating the primary instance of the queue manager.

     -rt a | s

     -rt s specifies that the DR configuration uses synchronous replication, -rt a specifies that the DR configuration uses asynchronous replication. Asynchronous replication is the default.

     -rl Local_IP

     Specifies the local IP address to be used for DR replication of this queue manager.

     -ri Recovery_IP

     Specifies the IP address of the interface used for replication on the server hosting the secondary instance of the queue manager.

     -rn Recovery_Name

     Specifies the name of the system that is hosting the secondary instance of the queue manager. The name is that value that is returned if you run uname -n on that server. You must explicitly create a secondary queue manager on that server.

     -rp Port

     Specifies the port to use for DR replication.

     other_crtmqm_options

     We can optionally specify one or more of these general crtmqm options:

     • -z
     • -q
     • -c Text
     • -d DefaultTransmissionQueue
     • -h MaxHandles
     • -g ApplicationGroup
     • -oa user|group
     • -t TrigInt
     • -u DeadQ
     • -x MaxUMsgs
     • -lp LogPri
     • -ls LogSec
     • -lc | -l
     • -lla | -lln
     • -lf LogFileSize
     • -p Port

     -fs size

     Optionally specifies the size of the filesystem to create for the queue manager, that is, the size of the logical volume which is created in the drbdpool volume group. Another logical volume of that size is also created, to support the reverting to snapshot operation, so the total storage for the DR RDQM is just over twice that specified here.

     QMname

     Specifies the name of the replicated data queue manager. The name is case sensitive.

     After the command completes, it outputs the command that you need tp input on the secondary node to create the secondary instance of the queue manager. We can also use the rdqmdr command on your primary node to retrieve the crtmqm command that you need to run on the secondary node to create the secondary queue manager, see Managing primary and secondary characteristics of DR RDQMs.

• To create a secondary DR RDQM:
  1. Enter the following command on the node that is to host secondary instances of the RDQM:

     crtmqm  -rr s [-rt (a | s)] -rl Local_IP -ri Primary_IP -rn Primary_Name  -rp Port [other_crtmqm_options] [-fs size] QMname

     Where:

     -rr s

     Specifies that you are creating the secondary instance of the queue manager.

     -rt a | s

     -rt s specifies that the DR configuration uses synchronous replication, -rt a specifies that the DR configuration uses asynchronous replication.

     -rl Local_IP

     Specifies the local IP address to be used for DR replication of this queue manager.

     -ri Primary_IP

     Specifies the IP address of the interface used for replication on the server hosting the primary instance of the queue manager.

     -rn Primary_Name

     Specifies the name of the system that is hosting the primary instance of the queue manager. The name is that value that is returned if you run uname -n on that server.

     -rp Port

     Specifies the port to use for DR replication.

     other_crtmqm_options

     We can optionally specify one or more of these general crtmqm options:

     • -z

     -fs size

     Specifies the size of the filesystem to create for the queue manager, that is, the size of the logical volume which is created in the drbdpool volume group. If we have specified a non-default size when creating the primary queue manager, you must specify the same value here.

     QMname

     Specifies the name of the replicated data queue manager. This must be the same as the name you specified for the primary instance of the queue manager. Note that the name is case sensitive.

What to do next

After we have created your primary and secondary instances of your queue manager, you must check the status on both nodes to check both are correct. Use the rdqmstatus command on both nodes. The nodes should be displaying normal status as described in Viewing DR RDQM status. If they are not displaying this status, delete the secondary instance and recreate it, taking care to use the correct arguments.