Testing a VDO volume and reviewing the stats

In order to test deduplication and compression, we will test with a big file, such as the RHEL 8 KVM guest image available at https://access.redhat.com/downloads/content/479/ver=/rhel---8/8.3/x86_64/product-software.

Once downloaded, save it as rhel-8.3-x86_64-kvm.qcow2 and copy it four times to our VDO volume:

cp rhel-8.3-x86_64-kvm.qcow2 /mnt/vm1.qcow2
cp rhel-8.3-x86_64-kvm.qcow2 /mnt/vm2.qcow2
cp rhel-8.3-x86_64-kvm.qcow2 /mnt/vm3.qcow2
cp rhel-8.3-x86_64-kvm.qcow2 /mnt/vm4.qcow2

This would be the typical case for a server holding VMs that start of the same base disk image, but do we see any improvement?

Let's execute vdostats --human-readable to verify the data. Note that the image downloaded is 1.4 GB, as reported by ls –si. The output obtained from vdostats --human-readable is as follows:

Device                   ...