Publisher upgrade

[pcromwell]

We have a large CUCM cluster of 7 servers. Operations are 24/7 so no downtime is allowed. However we have resilience so can bring down 1 server at a time with no service loss. We need to go from 9.1 to 11.5 and also migrate to new hardware. (PCD not an option)  because of outage contraints I am going to upgrade Pub into inactive partition. This will allow me to then upgrade the Subscribers ,TFTP and IM&P servers into Inactive partition. I will be left with a 9.1 version live and all servers will have 11.5 in inactive partition. that will allow me to systematically reboot cluster into 11.5 over a 12 hour period.

However as they make changes to dbase everyday. there is going to be a 3 week gap before we can get all servers onto 11.5 in the inactive partition. This will mean Publisher will be out of date when switch to 11.5.

My idea on the day before due to switch versions, is to upgrade the publisher again into the inactive partition with exact same 11.5 version as used before, This will then give me an up to date databse

1. Will the publisher allow itself to be upgraded again?

2. When the subs,TFTP's and CUPs are switched, will they accept the new upto date publisher database records?

[Ayodeji Okanlawon]

This is going to be a refresh upgrade and that means you cant do this while the CUCM server is functioning. This upgrade involves several server reboots, so you need to plan this for a maintenance window.

[pcromwell]

Yes, I know we are going to have reboots on each server, that is fine, we can have outage windows for one server at a time. but I would like to do the upgrade on the publisher twice due to not being able to switch over versions for 3 weeks from initial upgrade.  Will the Publisher allow this as the second time I try to upgrade it will be the exact same version in the inactive partition. Also as the Subs etc will have been upgraded 3 weeks prior, will they get updated by the Pub once the switch version has been performed?

[Ayodeji Okanlawon]

No, you cant upgrade the same version twice. CUCM will detect that the version on the inactive partition is the same as the one you are trying to upgrade and will not allow this

[Ayodeji Okanlawon]

When you switch versions on both Pub and Sub, there is going to db replication between all the nodes in the cluster. So yes publisher will attempt to sync its database to all subscribers once they are all on the same version

[pcromwell]

I would have thought that as well, but on another post (see below link)someone has tried it and it seems to work. I was hoping someone could confirm it. I could of course try and and see. I would be interested to know if the other subs would re-synch all data after Pub has been upgraded for a second time, so that all servers will have the latest dbase info

https://supportforums.cisco.com/t5/ip-telephony/installing-same-cucm-version-inactive-partition/td-p/2358844

[Ayodeji Okanlawon]

CUCM 9.1 is different from CUCM11.5, so this  may not be possible. I have not done it myself. I will suggest you ask Cisco if this is indeed possible