CUCM 7.1 on MCS migration to 8.6.2 on UCS

[fxavoip12]

Hi All,

I am in the middle of the migration from CUCM 7.1.3 on MCS to 8.6.2 on UCS, based on my research I must:

1- Upgrade 7.1.3 to 8.6.2 on the MCS ( Publisher), then udo  DRS and get the backup.at this point Phones working fine, but subs are

still 7.1.3 .Based on the Cisco website, I must upgrade all nodes on the Cluster then get the backup. at this stage PUB is on 8.6.2 but all the services are inactice except the one for DRS.

Question: why I should upgrade all the cluster, I want to do the follwoing:

1- Shut down all SUBs on MCS( Production)

2- Upgrade PUB from 7.1 to 8.6 on UCS.

3-do DRS to get the backup

4- switch back PUB to 7.1

5-turn on the SUBs( at tis stage our production working fine)

6- then go to the UCS and restore the backup.

7- if there is no issue, replace the UCS with MCS.

Is that a correct order?

Can I switch back from 8.6.2 to 7.1 on MCS once I get the DRS?

Why should I upgrade all clusters ( which are on mCS) to 8.6 in order to get the DRS? why we cannot upgrade PUBs and then do the backup.

Thank you,

Hamed

[Vipul Jindal]

# if you are not upgrading all the subs to 8.6.2, in that case you have to re install all the subs and they will get the database copy from PUB(UCS), you will only miss the MOH files you have installed on individual server.

# yes you can swtich back to 7.1 on MCS after you get the DRS.

thanks,

Vipul Jindal

[fxavoip12]

Hi Vipul,

You mean as I do now want to migrate to 8.6 on MCS , as soon as I upgrade my Publisher on MCS and get the bckup, should be enough.no need to upgrade my cluster in order to get the backup?

[Vipul Jindal]

no, if you are planning to install the subscriber in UCS fresh!!

thanks,

Vipul Jindal