Drbd partition mount check bash one liner

This is just a quick tip for you out there that use DRBD in simple Primary/Secondary mode and need to check whether a script is executed on the node which is currently Primary and has the Drbd Filesystem mounted. Let's just say you need to copy stuff onto your Drbd partition via a cron script. You can use the following one liner which is checking on the device '''/dev/drbd0''' which you probably need to adept to your needs and will print a message to standard output if this is the node which is holding the resources. Just replace that message output with the command you would like to execute and you are good to go.

if [ "`mount | grep /dev/drbd0 | wc -l`" == "1" ]; then echo "We are holding the resources"; fi