HA And vMotion in Vmware

1.              HA 5.0

• Uses an agent called FDM - Fault domain manager
• HA now talks directly to hostd instead of using vcenter agent vpxa
• Master/slave concept
• Master
• monitors availability of hosts/VMs
• manages VM restarts after host failure
• maintains list of all VMs in each host
• restarting failed VMs
• exchanging state with vcenter
• monitor state of slaves
• Slave
• monitor running VMs and send status to master and performs restart on request from master
• monitors master node health
• if master fails, participates in election
• Two different heartbeat mechanisms - Network heartbeat and datastore heartbeat
• Network heartbeat
• Sends between slave and master per second
• When slave is not receiving heartbeat from master, checks whether it is isolated or master is isolated or has failed
• Datastore heartbeat
• To distinct between isolation and failure
• Uses ‘Power On’ file in datastore to determine isolation
• This mechanism is used only when master loses network connectivity with hosts
• 2 datastores are chosen for this purpose

• Isolation response
• PowerOff
• Leave Powered On
• Shutdow

vMotion -

• vMotion enables live migration of running virtual machines from one host to another with zero downtime
• Prerequisites

1. Host must be licensed for vMotion
2. Configure host with at least one vMotion n/w interface (vmkernel port group)
3. Shared storage (this has been compromised in 5.1)
4. Same VLAN and VLAN label
5. GigaBit ethernet network required between hosts
6. Processor compatibility between hosts
7. vMotion does not support migration of applications clustered using Microsoft clustering service
8. No CD ROM attached
9. No affinity is enabled
10. vmware tools should be installed