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Changing the IP addresses used for replication

You may need to change the host name or IP address of the Primary and Secondary used for replication if you move a Primary or Secondary to a new location or if you need to make the replication use a different network. You can change the host name or IP address even after replication has been established. The vradmin changeip command enables you to change the replication network between the Primary and a Secondary in an RDS.

Prerequisites for changing the IP addresses used for replication:

  The new host names must be configured for proper resolution at both the Primary and Secondary sites using the appropriate mechanisms such as DNS, NIS, or hosts. This means that each system must be configured to bring up their addresses on reboot, or if this is a cluster, the cluster monitor must bring up the proper address.

  The Secondary must be reachable from the Primary either through the previous network, the new network, or both the networks.

  If the previous network is no longer available, the vradmin changeip command must be run from the Primary host.

  Note   The VVR heartbeat port can be changed using the vrport command. To ensure that the RLINKs pick up the new port, always run the vradmin changeip command (without passing the newpri and newsec arguments) after changing the port. Restart the vxnetd daemon on the required system for the changes to take effect.

 To change the IP addresses used for replication

vradmin [-g diskgroup] changeip local_rvgname [sec_hostname] \

[newpri=<new_pri_ip | hostname>] [newsec=<new_sec_ip | hostname>]

The argument diskgroup is the name of the local disk group that contains the RVG.

The local_rvgname argument is the name of the RVG on the host where the command is issued.

The sec_hostname is the name of the Secondary to which the replication network is being changed. This argument must be specified if the RDS has more than one Secondary.

The newpri attribute specifies a new hostname or IP address for the Primary host that is to be used to establish a network connection for the replication to the Secondary. This is the new value for the local_host attribute of the Primary RLINK and the remote_host attribute of the corresponding Secondary RLINK.

The newsec specifies a new hostname or IP address for the Secondary host that is to be used to establish a network connection for the replication. This is the new value for the remote_host attribute of the Primary RLINK and the local_host attribute of the Secondary RLINK.

Example:

This example shows how to change the network used for replication. The current configuration looks like this:

After making the changes to the replication network, the configuration looks like this:

 To change the IP addresses used for replication

1. From the Primary host seattle, issue the following command:

   # vradmin -g hrdg changeip hr_rvg newpri=seattle_hrnet \
newsec=london_hrnet

   The vradmin changeip command changes the IP address of both the Primary RLINK and the corresponding Secondary RLINK to the new addresses newpri and newsec (in this example, seattle_hrnet and london_hrnet, respectively).

2. To verify the change on the Primary RLINK, issue the following command on the Primary host:

   # vxprint -l rlk_london_hr_rvg

   Output includes the following fields:

   Disk group: hrdg
   .
   .
   Rlink: rlk_london_hr_rvg
   .
   .
   remote_host=london_hrnet IP_addr=x.x.x.x
   .
   .
   local_host=seattle_hrnet IP_addr=x.x.x.x
   .
   .

   where x.x.x.x represents the corresponding IP address.

3. To verify the change on the Secondary RLINK, issue the following command on the Secondary host:

   # vxprint -l rlk_seattle_hr_rvg

   Output includes the following fields:

   Disk group: hrdg
.
   .
   Rlink: rlk_seattle_hr_rvg
   .
   .
   remote_host=seattle_hrnet IP_addr=x.x.x.x
   .
   .
   local_host=london_hrnet IP_addr=x.x.x.x
   .
   .

   where x.x.x.x represents the corresponding IP address.