Last night we upgraded one of our CallManager 7 clusters to a new minor version to resolve issues and to apply the usual bug fixes. We were moving from 7.1.3.33024-1 to 7.1.5.30000-1, which in the past we had not noticed any issues with.

In preparation, we preloaded 7.1.5.30000-1 about a week before the upgrade was scheduled to take place to reduce time in the outage window. After the upgrade had completed, we noticed that we were missing data, or that data had returned to previous values. The most obvious changes were to route patterns mobile connect setups (due to end user visibility), however other data loss may have also occurred.

We looked at the system and realised that our missing or modified data was any changes that had occurred in the week that the upgrade had been preloaded. It seemed that a database snapshot had been taken when we preloaded  7.1.5.30000-1 and that any changes made to 7.1.3.33024-1 had been ignored once the upgrade was applied.

We trolled through the install logs but could not find any errors during the upgrade or reason as to why this occurred.

The Cisco site doesn’t have any upgrade documentation for 7.1, but a similar doc from 6.1(1) states: Your configuration information migrates automatically to the upgraded version in the active partition. http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/cucos/6_1_1/cucos/iptpch7.html#wp1040186

Needless to say we will not be preloading future updates and that everything will be performed inside of the outage window to minimise data loss.