Best way to update CUCM Cluster

[mpieper]

Hi everyone,

I have a few questions on what the best way to update a CUCM Cluster is.

The cluster is running 10.5.2.12901-1, and i plan to upgrade it to the latest 10.5.2 version (currrently 10.5.2.16901-1). I would also like to install the latest Device Pack to enable support of 8821 phones. And finally we also have issues with daylight-savings time, so I would like to install the latest time zone update as well.

How would I go on to install those all? Do i even need the time zone update if i update the callmanager version anyway?

There are 5 servers in our cluster: The publisher, two servers running the callmanager service, and two others running TFTP. I need to keep impact on call processing low, but short interruptions are acceptable. At the same time I have to keep the total updating time as short as is reasonable.

This is how I would install a single of those things above, please correct me if I'm wrong, I never did a callmanager upgrade of an already deployed cluster:

1: Install on publisher, if applicable do not switch version. Wait until it is done.

2: Install on all 4 subscribers in parallel, again without version switch if applicable. Wait until all are done.

3: Reboot/Switch version on the publisher. Wait until it is back up.

4: Reboot/Switch the first call processing node. The phones will re-register to the secondary. Wait until it is back up

5: Reboot/Switch the second call processing node. The phones will re-register on the primary. Wait until it is back up.

6: Reboot/Switch the two TFTP Servers at the same time. Wait until they are back up.

7: Verify versions on all nodes, verify database syncronisation.

Can I install all three, and only then switch versions? If so, would the order matter? Or do I have to install the CUCM upgrade, switch version, can then install both Device Pack and Timezone Update at the same time?

[Slavik Bialik]

Yeah, the steps you've wrote seems OK to me.
About the patches, device packages and timezone update, you can install them at once, and then you'll have to restart the CUCM. But of course do it AFTER you've upgraded all your servers and switched all versions.

[mpieper]

Thank you.

So I can't do this in one single step, but I do not have to reboot three times.

Another thing that I just now considered: I have a SIP Trunk that requires an MTP. I have those MTPs set up on two servers in my cluster. If an MTP is currently in use on a specific server, and that server reboots, the call using that MTP would be terminated I assume? If so, how can I see the current MTP usage? Or will the call be switched to a secondary MTP in the same MRGL?

[Slavik Bialik]

A current call using MTP resource will be disconnected. A new one, of course will use the other available MTP resource.
You can see the MTP usage in the RTMT tool. Very easy.
And I would advise you not to do that in the middle of the day, but only after working hours. Plus, you can prioritize the MRG resources in the MRGL. Actually, create 2 MRGs, each MRG will contain a resources of a different CUCM, for example: MRG-Sub1, MRG-Sub2, and then in your MRGL you can both of them and prioritize them. So if you're restarting the Sub1 server, just prioritize the second to be the first one, wait a 10-15 minutes for most of the calls on Sub1 to be disconnected, and then restart the server.

[mpieper]

Thank you again.

Just two last (for now ;)) questions:

Do I even need to install the Device Pack or Timezone Update anymore after I have installed the Upgrade?

I just did some testing in a lab environment, upgrading it to 10.5.2.16900. After the upgrade, I can see 8821 in the dropdown when I try to add a new phone. The 8821 is not available on our current PROD version (10.5.2.12901).

Second question: If I install the upgrade, but do not switch immediately, do I loose all changes that have happened in between?

[Slavik Bialik · Accepted solution]

After you're upgrading and switching the version, just do the following command in the CLI:
show timezone config
It'll output you the time-zone version installed currently on the CUCM. And if you see that there's a newer version available for this CUCM, I would go and install it after the swtich.
About the device pack, if you're upgrading the newest SU, you don't need to install any other device packages, as you'll have the most updated one already installed.
About your last question, I wouldn't do it. I would first switch the version, and if you'll need to install something like time-zone update so do it after the switch process. I wouldn't take any chances on doing it before the switch process, although it may work.