I have a KVM virtual stack of about 10 v-machines on a CentOS 5 host. Now the perceived efficiency of the whole virtual stack has dropped. The load averages may be low, but still the systems sometimes hang for even more than a minute. Apache does not serve, email is delayed, etc. I was wondering if there might be a connection with this: I recently added my first CentOS 6 guest to this virtual stack. Could a CentOS 6 guest somehow behave badly on a CentOS 5 host?? - Jussi