LCM simplifies Nutanix IT infrastructure life cycle operations by consolidating software and firmware component upgrades into a unified control plane.

Prerequisites

·   It's recommended to have a cluster with at least three nodes to perform a normal rolling hypervisor upgrade.

·   The 2-node case isn't well supported and might require extra steps to enable rolling upgrades, like installing and configuring a Witness VM.

·   The 1-node cluster upgrade is also supported but requires LCM 2.2.3 or newer.

·       LCM 2.0 is considered old and not recommended for the AHV upgrades, instead one has to use the legacy "Upgrade Software" method in "Settings".

·       Starting LCM 2.2.3, AHV upgrade is supported, both single node cluster and regular cluster, but it only support el6 based AHV upgrade.

·       Starting LCM 2.3, AHV upgrade is fully supported, single node, multiple nodes cluster, upgrade from el6 based AHV to el7 based AHV, el7 based AHV to el7 based AHV, UEFI el7 based AHV to UEFI el7 based AHV.

·       A newer version of LCM may require a newer version of AOS, since LCM framework code is interacting with the genesis code. This means, if you keep AOS 5.10.x and upgrade LCM to 2.2 or master, LCM may not work well.

Upgrade AHV through LCM

Step 1, On Prism Element UI, click "LCM" to enter LCM page

Step 2, Click "Perform inventory". This will have the LCM framework updated to the latest (2.3.0.1 as of 14 Jan 2020) and also scan available AHV upgrade candidates.

Click "OK" to confirm

After a successful inventory, you'll see LCM framework upgraded to 2.3.01; Software (here AHV) has 3 entities ready to upgrade

Step 3, Perform the upgrade.

Check mark  Softwares à "AHV Hypervisor", then click "Update" button

Depending on how heavy the cluster is loaded, each node may take 25 minutes or more to complete the upgrade.