[pve-devel] [RFC cluster] node add: replace force with fine grained paramters

[Thomas Lamprecht]

On 11/11/2016 06:39 AM, Dietmar Maurer wrote:
>> force was an 'overwrite every possible problem' flag, which can
>> have bad results.
>> For example an user could be OK that the local machine has already
>> some VMIDs configured but not that corosync is running, with the
>> '-force' parameter he has no choice than overwrite both or none.
>> He even gets no warning from the checks if he uses force.
> I don't really understand why that makes sense? When (and how often) does
> a user run into that problem?

rebuilding a cluster (after upgrading to new major PVE version) for 
example, there he has to use the --force param, if something else is 
broken (i.e. corosync still runs) this can be problematic, because he 
gets not even notified by the failed check.

We currently say to the users the should use `pvecm add --force`  on 
cluster rebuild, now we could say use `pvecm add --allow_vmids` and we 
could ensure that other problems trigger an error.

Also from forum post I saw that the -force option is an 'one cure for 
all' solution, if adding not works a lot just add the force param, now 
the have more fine grained control.

I guess it's not seldom the case that a user has to single PVE nodes 
with VMs already running, now -force is an overkill, if the user checked 
that he has no VMID conflicts he can safely use 'allow_vmids' and has 
not to worry that he missed something and corsync ran already on both.

I had to deal with a few broken clusters in support and there I often 
wished this, I mean I think through twice what I do but still I wished 
that I can do cluster adds safer in such situations.

maybe it irked just me, so other opinions would be welcomed.
Also we can let the force option if wished, which overwrites all, but at 
least gives warnings of the checks it overwrote.