The disk space used during the upgrade process depends on how the hypervisor internally handles the disk lifecycle for an instance. The following table shows Ribbon's recommendation for extra disk space for different flavors of the SBC SWe, PSX, and EMS: *Extra disk space (in addition to the disk space requirement for the instance) is only applicable during the upgrade process. Total disk space requirement during upgrade = Disk Space for the upgraded instance + extra disk space required only during upgradeMinimum Disk Space Requirements for SWe Upgrades