[ClusterLabs] Moving resources and implicit bans - please explain?

[Matthew Mucker]

I have set up my first three-node Pacemaker cluster and was doing some testing by using "crm resource move" commands. I found that once I moved a resource off a particular node, it would not come back up on that node. I spent a while troubleshooting and eventually gave up and rebuilt the node.

After rebuild, the same thing happened. I then found in the documentation for the crm_resource command under the move command "NOTE: This may prevent the resource from running on the previous location node until the implicit constraints expire or are removed with −−unban"

This is a regrettably vague note. What dictates the conditions for "may prevent?" How do I determine what implicit constraints are present on my resources and when they'll expire?

I did find that explicitly removing bans with crm_resource -U solved my problem. However, I'd like to understand this further. Any explanation would be appreciated. A Google search on "pacemaker move resource ban" didn't find me anything that was obviously authoritative.

I'd appreciate any expertise the community could share with me!

Thanks,

-Matthew