Upgrade Methods
You can use one of these two main methods to upgrade components within Cisco HCS:
Direct Upgrades
A direct upgrade is when you install the new software on the same physical device or the same virtual server where the current version is installed. Direct upgrades allow you to upgrade from your current release to the latest release without the need to upgrade to an intermediate software version. It is a single-upgrade rather than a multi-hop upgrade.
There are two types of direct upgrade:
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Standard upgrades
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Refresh upgrades
Standard upgrades
Standard upgrades are upgrades that do not require upgrades to the embedded operating system. You can install upgrade software on your device while the system continues to operate.
For standard upgrades, you install the upgrade software as an inactive version. The system continues to function normally while you install the software. When the upgrade is complete, you can choose to automatically reboot the system to the upgraded software or you can manually switch to the new software later. When you reboot to the new software, the old software version remains on the system. This allows you to revert to the old version in the unlikely event of issues with the new software. During an upgrade your configuration information migrates automatically to the upgraded version.
Refresh upgrades
You can use the Refresh upgrades in situations where incompatibilities exist between the old and new software releases. For example, use a refresh upgrade when the major version of the embedded operating system changes between the version you are upgrading from and the version that you are upgrading to. Refresh upgrades require multiple reboots during installation to upgrade the underlying operating system, causing a temporary outage while installing the software. The duration of this outage depends on your configuration.
Note |
You must perform all refresh upgrades during a maintenance window because the system is not available during the upgrade. |
Migrations
A migration is an upgrade where the new software is installed on a different hardware system or virtual machine than the currently installed version. Some examples where you need to use the migration method on UC applications are as follows:
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The currently installed version is running on Cisco 7800 Series Media Convergence Server (MCS 7800) hardware and you are upgrading to release that will run on a virtual machine.
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The currently installed version is running on a virtual machine and you need to move to a new virtual machine.