When setting up DRBD in an active/passive configuration with XFS as the file system, is it necessary to configure STONITH (Shoot The Other Node In The Head)? Is there is much benefit? Or its not required.
It’s not “required”, but there are certain situations where it might help you.
- If a process accessing the XFS filesystem enters an uninterruptible sleep or zombie state, you could end up in a situation where cluster services are hung, but failover cannot happen because the hung process is holding the DRBD device’s mountpoint open.
- In two node clusters you could end up with divergent data (split-brain) that would need to be resolved manually. In three+ node clusters you can use DRBD quorum to prevent this.
Because DRBD is a “shared-nothing” replicated storage solution, as long as you’re running in “active/passive” and don’t enable dual-primary mode, you don’t really run the risk of corruption without STONITH like you might with other shared storage solutions.