Which incremental backup mode should I use to backup my Citrix Hypervisor/XenServer VMs? CBT, SpeedKit or Ordinary?
CBT: Changed Block Tracking is an advanced feature supported on XenServer 7.3 and higher versions, but to be able to use the CBT API, your Citrix Hypervisor/XenServer must be Premium edition.
So, if you are running XenServer 7.3 or higher versions and licensed as Premium edition, it's recommended to use CBT as the incremental mode.
If you are running XenServer older versions (under 7.3) or your Citrix Hypervisor/XenServer is free or standard edition, please do not enable CBT, otherwise the backup will fail.
SpeedKit: SpeedKit is a Vinchin unique feature which can be applied to all Citrix Hypervisor/XenServer versions and licensing editions, it can be used as a CBT alternative if CBT is not available.
When SpeedKit is enabled, a snapshot needs to be reserved for each VM for faster calculation of the VM increments. If you have sufficient production storage, and CBT is not available, SpeedKit is the recommended incremental mode.
Ordinary: Ordinary mode also applies to all Citrix Hypervisor/XenServer versions and licensing editions. If your Citrix version or licensing edition does not support CBT, and also you have limited production storage which does not allow you to use SpeedKit, then you need to use the Ordinary incremental mode.
Running incremental backups with Ordinary incremental mode, the backup session time will be longer than both CBT and SpeedKit.
For stability issue, it's not recommended to use CBT as the incremental mode if your XenServer version is 7.3. For 7.4 and higher versions, CBT should work fine.