On 2019-07-15 16:29:47 +0200 (+0200), Giuseppe Sannino wrote:
[...]
> Once logged in the VM is not too slow. CLI doesn't get stuck or similar.
> One thing worthwhile to mention, it seems like the writing throughput on
> the disk is a bit slow: 67MB/s  wrt around 318MB/s of another VM running on
> a "datacenter" Openstack installation.
[...]

Have you checked dmesg in the guest instance to see if there is any
I/O problem reported by the kernel? The login process will block on
updating /var/log/wtmp or similar, so if writes to whatever backing
store that lives on are delayed, that can explain the symptom.
--
Jeremy Stanley