The backupConfig command is a simple utility to backup the configuration of your node to a file. Before executing this command make sure that your configuration is in the consistent state and then synchronize to all the nodes.
When you execute backupConfig command it will storp the node before backup is made so that partically synchronized information is not saved so you can specify -nostop command line parameter so that the backup is taken without stopping the server
I took backup of my DMGR and it took couple of minutes to execute
After backup was taken i looked at the WAS_DMGR_08_24_2009.zip and this is how its content looks like
As you can see it took backup of PROFILE_HOME/config directory