We have over 50 FreeBSD VM on KVM for years, several Proxmox (5x,6x) and Centos (6.x,7.x) servers, and never experienced performance problem like this. Your example on fresh new 13 VM: # time -p find / -name cacert.pem real 0.28 user 0.00 sys 0.13 12.2 our syslog server: # time -p find / -name cacert.pem real 4.12 user 0.21 sys 3.77 Our hardware are Supermicro, IBM and Fujitsu servers with Xeon CPU-s, some with HW raid, others with ZFS as datastore, previous we had several IBM x3650 ... Everything was ok. No big difference between Linux and FreeBSD guests. We use Linux as guests only if we have to.