Abstract: Methods, systems and computer readable medium for fast cluster upgrades. The disclosed techniques can be applied during an upgrade of a multi-node cluster when upgrading cluster software and/or hardware. Techniques applied include pausing a virtual machine (VM) at a first node, then communicating then-current states of the paused VM to a second node that executes a migrated clone of the paused VM. While the migrated cloned VM is running at the second node, changes to states of the cloned VM are tracked. When the upgrade of the first node has completed, then when migrating the cloned VM back to the first node, only the tracked state changes of the cloned VM are sent from the second node to the first node. The tracked state changes are used to update the states of the paused VM at the first node. The updated VM is resumed at the first node.

Abstract: Methods, systems and computer readable medium for fast cluster upgrades. The disclosed techniques can be applied during an upgrade of a multi-node cluster when upgrading cluster software and/or hardware. Techniques applied include pausing a virtual machine (VM) at a first node, then communicating then-current states of the paused VM to a second node that executes a migrated clone of the paused VM. While the migrated cloned VM is running at the second node, changes to states of the cloned VM are tracked. When the upgrade of the first node has completed, then when migrating the cloned VM back to the first node, only the tracked state changes of the cloned VM are sent from the second node to the first node. The tracked state changes are used to update the states of the paused VM at the first node. The updated VM is resumed at the first node.