After reading the Manual from Red Hat I have been notifieded about non-supported configurations
The following configurations are not supported:
Under Ubuntu I currently have got an raid 10 (software) with HDD's and using bcache with two SSD's in raid 1 (software) which is unfortunately still not supported by CentOS 8. And VDO on top of LVM Cache seems not supported by VDO.Red Hat wrote: VDO on top of VDO volumes: storage → VDO → LVM → VDO
VDO on top of LVM Snapshots
VDO on top of LVM Cache
VDO on top of the loopback device
VDO on top of LVM Thin Provisioning
Encrypted volumes on top of VDO: storage → VDO → DM-Crypt
Partitions on a VDO volume: fdisk, parted, and similar partitions
RAID (LVM, MD, or any other type) on top of a VDO volume
Do I have got any available alternative for read and write caching with SSD's in front of HDD's by usage with VDO?
cheers Darko