vcsa 5.5 to 6.0 upgrade - not enough vcpu on host

Hi gents,

I ran to a problem today. I am trying to upgrade our VCSA 5.5 to 6.0

5.5 config - 2vCPU, 16GB RAM, managing 22 hosts with 200 VMs

I tried to make an upgrade, but it tells me, that the Appliance size could be either Medium (400 hosts/4000 VMs) or Large (1000 hosts/10 000 VMs) and that it takes 8vCPU/24GB RAM/300GB disc space.

The target HW is IBM X3650M3 with 1 socket/6 cores per socket/12 logical processors Intel Xeon L5640 with enough RAM and enough disc space on local SSD.

The same machine is running the old 5.5 VCSA.

What could be the reason to go from 2vCPU to 8vCPU and from Small to Medium ? Amount of logs or historical data ? If so, how to "shrink" them in the old VCSA ?

Thanks in advance and best regards

Jakub Cikhart from sunny spring Prague ..