Comment 2 for bug 1555676

Marking incomplete as I believe this is a node running out of memory, see the paste:

"FileTypeCrontab could not read root: Cannot allocate memory "

The issue is we've added a number of new features to the overcloud, and until we have composable services they are all enabled by default - this means our RAM requirements have crept up so I'd suggest allowing 8G for the controller nodes.

With KSM (enabled by default on centos) you can overcommit with VMs so you can e.g have 4 or 5 8G VMs on a 32G host and things should work OK.