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Community Member

CUCM switch versions


We are planning to switch versions of CUCM from 6.1(2) to 6.1(4a)SU2 as an interim upgrade to v7.1(3). The 6.1(4a)SU2 files have been loaded into the inactive partition on all three CUCMs in cluster - all that is left to do is switch versions (PUB first, then two subs. I am just looking to see if there are any gotchas in this upgrade. The 6.1(2) OS doc doesn't go into great detail about the process other than do PUB first and then SUBS - if anybody has any input or info on things to look out for it would be appreaciated - also any idea on the time needed for a 3 CUCM cluster - we are scheduling a late night window to avoid user impact

Thanks in advance!


Re: CUCM switch versions

Any changes you made after the upgrade and before the switch will be lost.

See details on


Community Member

Re: CUCM switch versions

Thanks for the reply...i have made a few changes that we need to keep since the upgrade file was installed into the inactive partition. Can I put a copy of v6.1(2) into the inactive partition again and do the upgrade to 6.1(4) in one day to avoid this problem?


Super Bronze

Re: CUCM switch versions


If you are still running the original version, just run the install procedure again at the start of your maintenance window.

This will reinstall on the inactive partition, and migrate the data again.



Aaron Please remember to rate helpful posts to identify useful responses, and mark 'Answered' if appropriate!

Re: CUCM switch versions

You may just do the upgrade again with 6.1.2 in active partition.  During the upgrade, the database will be copied/migrated to the inactive partition (6.1.4).


Community Member

Re: CUCM switch versions

Yeah just doing the 6.1(4) upload again on migration day/night is probably the easiest and cleanest way - thanks very much to all for responding!!


Re: CUCM switch versions

One thing I sometimes do is upgrade the phone firmware loads on the active system to match the loads on the system that I am installing to the inactive partition. I then reset the phones in a controlled manner to allow them to update the firmware.

This way when I switch CUCM versions the phones just re-register and do not have to go through the entire firmware upgrade process. It saves lots of time and allows me to start my testing earlier. It also makes switching back CUCM versions easier.

I do not always do this with small deployments but, for larger ones with multiple sites, it simplifies things.

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