This can be enabled/disabled with the following crm_attribute commands:

crm_attribute -t nodes -N <nodename> -n maintenance -v on
crm_attribute -t nodes -N <nodename> -n maintenance -v off

We will add a pcs command to simplify that creation.

I don't think there is an "ask interactively" precedence in pcs
(putting auth aside), but in case of any resource running (or just
defined ... or just always) it would be good to ask the user if she
indeed wants "pcs cluster standby --all" or rather enable the maintenance
mode.  Or just apply this logic without asking as this should definitely
be more sane thing to do.

In case you don't like "standby --all" -> maintenance mode trigger
proposal, you may, at least, consider translating that command into
"pcs property set stop_all_resources=true" that would likely avoid 
inevitable issue with iterated switch toggling -- evacuation
of the resources to the rest of living nodes (until they are
standby'd as well) connected with unnecessary and unhelpful
utilization peaks there (there are some risks implied).

Jan, I didn't suggest that there should be a dialog or something asking the if somebody wants to put a node in standby mode or maintenance mode. All I'm asking for  is to be able to enable/disable maintenance mode via pcs, without having to fall back to using "crm_attribute".

Frank, I was talking about possibly bad behavior of "pcs cluster
standby --all" which could not be translated into enabling maintenance
mode as pcs hasn't be able to do that yet.  With this bug resolved
it will be, hence proposing translating that command to maintenance
mode enablement (implicitly or explicitly).  Is it more clear now?

Created attachment 1085139 [details]
proposed fix

Before Fix:
[root@rh67-node1 ~]# rpm -q pcs
pcs-0.9.139-9.el6_7.1.x86_64
Pcs does not have ability to put a node to maintenance mode.



After Fix:
[root@rh67-node1:~]# rpm -q pcs
pcs-0.9.145-1.el6.x86_64
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: rh67-node1 rh67-node2 
 Standby: 
 Maintenance: 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline: 
[root@rh67-node1:~]# pcs node maintenance
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: rh67-node2 
 Standby: 
 Maintenance: rh67-node1 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline: 
[root@rh67-node1:~]# pcs node unmaintenance
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: rh67-node1 rh67-node2 
 Standby: 
 Maintenance: 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline: 
[root@rh67-node1:~]# pcs node maintenance rh67-node2
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: rh67-node1 
 Standby: 
 Maintenance: rh67-node2 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline: 
[root@rh67-node1:~]# pcs node unmaintenance rh67-node2
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: rh67-node1 rh67-node2 
 Standby: 
 Maintenance: 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline: 
[root@rh67-node1:~]# pcs node maintenance --all
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: 
 Standby: 
 Maintenance: rh67-node1 rh67-node2 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline: 
[root@rh67-node1:~]# pcs node unmaintenance --all
[root@rh67-node1:~]# pcs status nodes
Pacemaker Nodes:
 Online: rh67-node1 rh67-node2 
 Standby: 
 Maintenance: 
 Offline: 
Pacemaker Remote Nodes:
 Online: 
 Standby: 
 Maintenance: 
 Offline:

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-0739.html