Rebuild CUCM Pub to increase HDD Size

[mumbles202]

Currently planning on redeploying a Pub using a the 7500 user template to increase the HDD size to 110 GB.  If the current Pub is still accessible, is building out the new nodes and then restoring it along from a good DRS backup the best option?  Or would the documentation for rebuilding a pub from the sub be applicable?  I suspect using DRS from the actual Pub would be better but it might just take a little longer.  Either way I'll have a maintenance window to perform the work.  

[Vaijanath Sonvane]

Hi,

In my opinion, the best option is to use Cisco PCD migration. You will have to deploy new OVA templates for CUCM nodes and configure the Cisco PCD with necessary tasks. Cisco PCD will migrate all data from old servers to new servers and it will gracefully shutdown old servers. This approach will have the least service impact with least amount of time as compared to re-building new CUCM nodes and restoring DRS backup. Please see Cisco PCD Administration Guide:

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/pcdadmin/12_0_1/cucm_b_pcd-admin-guide-121a/cucm_b_pcd-admin-guide-121a_chapter_01011.html

You can also refer to this video:

https://www.youtube.com/watch?v=Kd7dvvP103E

Make sure you do not change host name or IP Address of CUCM during migration process as this will regenerate CTL/ITL files and security certificates which can cause phone registration issues.

[mumbles202]

Thanks for the reply.  That would be another option to take.  How does PCD work if I'm on say 10.5 SU3 as opposed to the base image of 10.5?  

[Vaijanath Sonvane]

You can always open a Cisco TAC case to get bootable image for base version or SU version. In the past, I did same thing and Cisco TAC published bootable images for requested version. You can also create bootable image from non-bootable files. Please check this post and video for more details:

https://community.cisco.com/t5/ip-telephony-and-phones/make-cucm-iso-10-5-2-bootable/td-p/2799479

https://www.youtube.com/watch?v=pfH1HzVYowE

[mumbles202]

Thanks.  I'll look into PCD as a possibility.  Other than that, is a DRS restore from the PUB the better option?  

[Vaijanath Sonvane]

Yes, DRS restore from the PUB is another option. Here is what I will do:

• Set the enterprise parameter Prepare Cluster for Rollback to pre-8.0 to True on existing CUCM cluster. Make sure to restart all required services. This step will download special ITL file on IP Phones that contains empty TVS and TFTP certificate sections. I will perform this step because phones will be moved from old cluster to new cluster and they will not trust new cluster until existing ITL files are erased from Phone. Please see below post for more detailed information:

https://community.cisco.com/t5/collaboration-voice-and-video/migrating-ip-phones-between-clusters-with-cucm-8-and-itl-files/ta-p/3108501

Please note, you can also use Bulk Certificate Export option instead of Rollback Enterprise Parameter.

• Take fresh backup of existing CUCM Cluster. DRS backup is recommended from all servers in the cluster to backup custom Moh and other tftp files which are not replicated from the Publisher.
• Deploy new OVA templates for CUCM Pub and Sub.
• Install new CUCM cluster with new IP Addresses and Host Name. This step will have both clusters up and running. Make sure the Security Password, DNS, Domain, NTP and CUCM version details are matching to old CUCM cluster.
• Verify that the database replication is good and services are running.
• Set the enterprise parameter Prepare Cluster for Rollback to pre-8.0 to True on new CUCM cluster. Follow the process in Step-1.
• Disable Auto Registration on new CUCM cluster. 
• Create a new vSwitch (for example vSwitch0) and Virtual Machine Port Group (for example Isolated_VM_Network) on your VM environment. Do not assign any physical adapter to vSwitch0. This step I perform because instead of shutting down the old CUCM servers, assign them to Isolated VM Network. So, If I want to revert back, it will be much quicker. 
• During maintenance window, move production CUCM servers to Isolated VM Network Port Group. Make sure they are not reachable from your network.
• Change IP Address and Host Name of new CUCM Pub and Sub. Make sure these setting matches with old CUCM Servers. Follow the process mentioned in below URL for changing IP Address and Host Name:

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/install/10_0_1/ipchange/CUCM_BK_C3782AAB_00_change-ipaddress-hostname-100.html

• Verify that the database replication is good and services are running.
• Follow the process to restore DRS backup on new CUCM cluster.
• Verify that everything is restored and working.
• Set the enterprise parameter Prepare Cluster for Rollback to pre-8.0 back to False on new CUCM cluster. Follow the process in Step-1.

These are high level steps. You need to follow the steps in detail and look for any issues. Use RTMT tool to gather IP Phone registration information, device count etc.

As I have said in my earlier post, PCD will be much easier than DRS backup in this case.