VMworld 2014: vSphere HA Best Practices and FT Preview

Session BCO2701. This was very fast paced, and I missed jotting down a lot of the slide content. If you attended VMworld then I recommend you listen to the recording to get all of the good bits of information.

vSphere HA – what’s new in 5.5

VSAN Support
AppHA integration

What is HA? Protects against 3 failures:

Host failures, VM crashes
host network isolated and datastore incurs PDL
Guest OS hangs/crashes and application hangs/crashes

Best Practices for Networking and Storage

Redundant HA network
Fewest possible hops
Consistent portgroup names and network labels
Route based on originating port ID
Failback policy = no
Enable PortFast
MTU size the same

Networking Recommendations

Disable host monitoring if network maintenanceis going on
vmkinics for vSphere HA on separate subnets
Specify additional network isolation addresses
Each host can communicate with all other hosts

Storage Recommendations

Storage Heartbaeats – All hosts in the cluster should see the same datastores

Best Practices for HA and VSAN

Heartbeat datastores are not necessary in a VSAN cluster
Add a non-VSAN datastore to cluster hosts if VM MAC address collisions on the VM network are a significant concern
Choose a datastore that is fault isolated from VSAN network
Isolation address – use the default gateways for the VSAN networks
Each VSAN network should be on a unique subnet

vSphere HA Admission Control

Select the appropriate admission control policy
Enable DRS to maximize likelihood that Vm resource demands are met
Simulate failures to test and assess performance
Use the impact assessment fling
Percentage based is often the best choice but need to recalculate when hosts are added/removed

Tech Previews of FT

FT will support up to v 4CPUs and 64GB of RAM per VM
FT now uses separate storage for the primary and secondary VMs
New FT method does not keep CPUs in lock step, but relies on super fast check pointing

Tech Preview HA