CUCM Upgrade when one node is unreachable

[systempause]

Hello ,

We are planning to migrate and upgrade (from vm to vm ) our cucm and imp cluster , we have 3 cucm nodes and 2 imp nodes .

But actually 1 cucm and 1 imp server is actually in shutdown state . (we are planning to open these servers later and upgrade them .)

You can see our current cucm dbreplication status  as below ;

Can we upgrade cucm and imp cluster in this situation ? And maybe one mounth later we will open powered off nodes and upgrade them also ...

BR,

[Nithin Eluvathingal]

Are you migrating or moving from one Vm to another ?

If migrating, what tool you are planning for migration?

are you planning to use pcd? 

Since the servers are in shutdown and not synced, I don’t think it’s  possible.

[systempause]

Hi ,

Yes we will them migrate with using PCD.

They  are running on BE6K and versiyon 11.x we will migrate them to another appliance and also upgrade to 12.5 .

[Nithin Eluvathingal · Accepted solution]

Since you are going to use PCD, cluster discovery will fail for old Cluster. 

Your option is to remove the Turned OFF server from cluster and add it later after the migration. 

[VON CLAWSON]

No, this will not work. 

1. the pre upgrade check will tell you that the replication status is not working. 

2. if you try to upgrade anyway the replication will never get back in sync. 

You will need to bring up the two nodes and make sure that replication is in synch. then upgrade. If you need to shut down those two servers after that would be fine. Or you can delete those two nodes from the configuration. Then verify that replication is working and then upgrade.

[systempause]

Yes i know pre-upgrade cop is checking database status and it will give a warning , but is it just a warning ? You are saying that replication will not sync .

We are not able to open these servers for now , if we delete these servers from cucm and imp cluster  , i know that we can not add them later so as a result  we will need to install new nodes instead of them . i guess there is no other solution in this situation .

[Nithin Eluvathingal]

Delete that nodes if you need to upgrade only turned on servers now and add subscriber node later.

[systempause]

Can i add same nodes after the upgrade ? Version mismatch does not cause any problem ?

[Nithin Eluvathingal]

Add it as a new node on the version 12.5.

[Roger Kallberg]

This would not be recommended. At the time of the upgrade the state of the cluster and the services on it should be in stabile state.