To find out what’s in the pipeline for CUCM 12.5, click here.
Check if your VMware spec needs changing and modify the appropriate settings in your VMware environment e.g. CPU, RAM and Disk-space which can all be done in your VSphere settings. See here.
Note: Changing the OS from Redhat to CentOS is mandatory.
Read the below guide in its entirety and understand the caveats based on the CUCM version you will be upgrading from. Pay particular attention to the Pre-upgrade and Post-upgrade tasks as these are the tasks that will be most unique to your environment. See here.
Access Cisco’s PUT (Product Upgrade Tool) and Submit the upgrade software request. What’s really neat about this tool is the ability to state the version you are upgrading from and to, which makes for significant less reading.
As always you will be starting off with the Publisher. Note your VMware image will need to be in a powered off state to perform this change because you will be modifying the VMware hardware settings and changing the OS from Redhat to CentOS so make sure you adhere to your organizations change control policies.
Shutdown your server by accessing it via SSH and enter the command utils system shutdown
Modify your VMware hardware settings spec according to the VMware spec document mentioned above and change the Guest Operating system from Redhat to CentOS, see below.
Once the Publisher is powered back up turn off the TFTP service on the Publisher. Access Cisco Unified Serviceability -> Control Centre Feature Services -> Select TFTP and stop the service.
Install the upgrade file from CUCM OS Administration -> Install/Upgrade and Select the Source to be either DVD/CD or Remote File System and click next. I selected DVD/CD and put the ISO file in the local Datastore of the CUCM VMware image (see below). If you select Remote file system you will need to perform the installation using an SFTP server which takes significantly longer!
Select the CUCM 12.0 upgrade file you placed in your VM’s datastore and select next.
You will be asked if the system should automatically reboot after the installation. Select an option based on your companies change control policy. I typically always select Do not reboot after the upgrade and reboot the Server manually after the installation using SSH and entering the command utils system switch-version.
The installation script will now run which can take between two to three hours depending on your database size. Always periodically check the Installation log below to see if any errors have occurred. Once the script has finished. You will receive “The system upgrade was successful” message.
Next, you will need to reboot the server and switch the version of CUCM using SSH and entering the command utils system switch-version
Once the Publisher is powered back up turn on the TFTP service. Access Cisco Unified Serviceability -> Control Centre Feature Services -> Select TFTP and Start the service.
Verify that your server has upgraded to the correct version by accessing CUCM OS Administration -> Show -> Software -> Verify the Inactive and Active version should reflect your software version numbers.
Next check the replication between all servers is good using both Unified Reporting and Cisco’s RTMT (Real Time Monitoring Tool).
Access Cisco Unified Reporting -> System Reporting -> Database Status Report -> Generate a new report. Check all the servers have a replication status of 2.
In RTMT, Choose CallManager -> Service-> Database Summary. Again check all servers have a replication status of 2.
The overall experience of this upgrade was generally straightforward except for deciding on the system reboot order. This was due to the fact that VMware hardware had to be modified in a powered off state which evidently increased the change control window because another system reboot had to take place after the upgrade!
Another observation I noticed was the need to wait for replication status between the Publisher and the Subscribers to update.
It is important to get familiar with the new Licensing model which is called Smart Software Licensing. In Smart Software Licensing, the licenses are now managed in the cloud without the need for PLM and PAKs. For more information, click here.