fence-agents

OCF Compliant Fence Agents

Fence agents were developed as device "drivers" which are able to prevent computers from destroying data on shared storage. Their aim is to isolate a corrupted computer, using one of three methods: - Power - A computer that is switched off cannot corrupt data, but it is important to not do a "soft-reboot" as we won't know if this is possible. This also works for virtual machines when the fence device is a hypervisor. - Network - Switches can prevent routing to a given computer, so even if a computer is powered on it won't be able to harm the data. - Configuration - Fibre-channel switches or SCSI devices allow us to limit who can write to managed disks. This is used by the Pacemaker cluster resource management.