[PVE-User] pve-cluster won't start with large ssh_known_hosts

[Dietmar Maurer]

> It would then follow that the known_hosts file in pmxcfs is just for deploying
> host keys for (1) hosts that are in the cluster and (2) hosts that are being added
> to the cluster.  For both cases, the set of host keys is quite small and well known.
> It would be just as good to register specific host keys into pmxcfs when adding
> the hosts to the cluster.

OK, think I know what you mean now ;-) What you say is correct. We already do
it that way for the authorize_key file. There is 'ssh-copy-id' for authorized key, and
I guess we need to implement something similar for known_hosts.

So we can generate/update the known_hosts file on 'pvecm add' time.

- Dietmar