In the past I setup some new Pacemaker clustered nodes with a fresh Debian Stretch installation. I followed our standard installation guide, created also shared replicated DRBD storage, but whenever I tried to mount the ext4 storage DRBD detached the disks on both node sides with I/O errors. After recreating it, using other storage volumes and testing my ProLiant hardware (whop I thought it had got a defect..) it still occurs, but somewhere in the middle of testing, a quicker setup without LVM it worked fine, hum..
github source
The LCMC is a GUI application that configures, manages and visualizes high-availability clusters. Specifically it manages clusters that use one or more of these components: Pacemaker, Corosync, Heartbeat, DRBD, KVM, XEN and LVM.