Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

CUCM Upgrade Process

I am upgrading a CUCm that does NOT have any subscribers. I have downloaded the upgarde to the call Manager and my plan was to reboot later not immediately after the upgrade.My question is from this point if I choose to continue does the phones service interruption to the users while the upgarde is upacking? Should I not continue until after hours. this has never been an issue for me as there are usually subcribers in the cluster to take over if necessary. Input is appreciated!

Cisco Employee

Re: CUCM Upgrade Process

During the install phase of CUCM all is done in the inactive partition.

This could cause some high CPU depending on load, # of phones, etc.

It's always recommended to do this during maintenance windows.

Since there is no failover here it's better to make sure no one (or almost no one) will be affected if by any chance there are problems.

They will certainly lose service while the versions are being switched and the new one fully starts.



If this helps, please rate



if this helps, please rate
Cisco Employee

Re: CUCM Upgrade Process

The Upgrade process uses significant amount of the server's resources - so running it after office hours would be a good idea. However, if you are running a pretty new version of CallManager, you can select I/O throttling :

Keep in mind that the upgrade will take a long time to complete, if I/O throttling is enabled for the upgrade.

If you decide to not reboot into the new version after the upgrade completes, please  note that any changes made between the time of the upgrade and the time of  'switch version' will not be ported over to the newer version.

- Sriram

New Member

Re: CUCM Upgrade Process

Thank You responders!

Your commentes and my original suspicions aligned.  I am waiting for the meaintenance windows.  Thanks Again!

CreatePlease to create content