Upgrading Cluster without switch version

Question

Hello, I just want to be clear to an upgrade I will be performing in future. We have CUCM cluster and want to know if it is possible to do the upgrade on the publisher (without switch version) and then continue to upgrade the subscribers, then switch version on all - or do I need to switch version on publisher before I can continue to update subscribers?
Also, I think that in the past, the upgrade takes a copy of the database when you upgrade, so you need to switch version soon after upgrade or you will loose any changes. Is this remain the case? Is this also the case for UCCX? I remember maybe reading in the past that it does the database differently.
Thanks to you all

Answer 1

Hi Ess,
In addition to the great tips from my friend Manish (+5)
You didn't mention the to/from CUCM versions but here is an example
User Provisioning
For upgrades from Cisco Unified Communications Manager Release 6.x, changes that are made to the following user-facing features get preserved after the upgrade completes:
•Call Forward All (CFA)
•Message Waiting Indication (MWI)
•Privacy Enable/Disable
•Do Not Disturb Enable/Disable (DND)
•Extension Mobility Login (EM)
•Hunt Group Logout
•Device Mobility
•CTI CAPF status for end users and application users
•Credential hacking and authentication
•Recording enabling
•Single Number Reach enabling
Upgrading a Cluster in Parallel
When you upgrade a cluster that is running a supported version of Cisco Unified Communications Manager 6.x to Cisco Unified Communications Manager 8.5(1),  begin upgrading the first node first. You can begin upgrading  subsequent nodes in parallel after the first node reaches a specified  point in the upgrade.
During the upgrade of the first node, view the installation log,  install_log_.log, by using the Software  Installation/Upgrade window in Cisco Unified Communications Operating System Administration  or the command line interface (CLI). You can begin the upgrade of the  subsequent nodes after the following information displays in the log:
PRODUCT_TARGET is
PRODUCT_NAME is
PRODUCT_VERSION is
You can also use the CLI to search for the relevant information in the install log by following this procedure:
Procedure
Step 1 List the install logs; for example:
file list install install_* date
install_log_2008-10-01.09.41.57.log     install_log_2008-10-08.12.59.29.log
install_log_2008-10-14.09.31.06.log    
dir count = 0, file count = 3
Step 2 Search the most recent install log for the string PRODUCT_VERSION; for example:
file search install install_log_2008-10-14.09.31.06.log PRODUCT_VERSION
Searching path: /var/log/install/install_log_2008-10-14.09.31.06.log
Searching file: /var/log/install/install_log_2008-10-14.09.31.06.log
10/14/2008 09:52:14 upgrade_os.sh|PRODUCT_VERSION is 7.1.0.39000-97|
Search completed
Step 3 When the file search command finds the PRODUCT_VERSION string in the install log, you can start the upgrade of the subsequent nodes.
Caution If  you want to upgrade the subsequent nodes in parallel with the first  node, do not choose the Reboot to upgraded partition on either first  node or subsequent nodes while configuring the upgrade options. If  selected, the first node may complete its upgrade and reboot while the  subsequent nodes are upgrading, which causes the upgrade of the  subsequent nodes to fail.
When you are ready to activate the new version, you must activate the  new software on the first node before activating it on all other nodes. .
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/8_5_1/cucos/iptpch7.html#wp1076243
Cheers!
Rob
"Seek it out and ye shall find  " 
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