Create a disaster recovery RDQM

You 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 create the RDQM as root.

We must create a primary RDQM DR queue manager on one node. Then 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 we 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 we need to 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 we need to run on the secondary node to create the secondary queue manager, see Manage 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 we 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, we 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 you have created your primary and secondary instances of our queue manager, we 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 View DR RDQM status. If they are not displaying this status, delete the secondary instance and recreate it, taking care to use the correct arguments.

• Delete a DR RDQM
  You use the dltmqm command to delete a disaster recovery replicated data queue manager (RDQM).
• Migrating a queue manager to become a DR RDQM queue manager
  We can migrate an existing queue manager to become a disaster recovery (DR) replicated data queue manager (RDQM) by backing up its persistent data, then restoring the data to a newly created RDQM queue manager that has the same name.
• Resizing the filesystem for a DR RDQM queue manager
  To resize the filesystem for an existing disaster recovery (DR) replicated data queue manager (RDQM) you back up its persistent data, then restore the data to a newly created RDQM queue manager that has the same name but a filesystem of a different size.
• Storing persistent application status
  We can store persistent status information relating to applications along with other queue manager data.

Parent topic: RDQM disaster recovery

Related information

• crtmqm