vMotion is used to move a powered on virtual
machine from one host to another
VMWare
vMotion can be be used to :
- Improve overall hardware utilization
- Allow continued virtual machine operation while accomodating
scheduled hardware downtime.
- Allow vSphere Distributed Resource Scheduler(DRS) to balance
virtual machines between hosts.
How
vMotion Migration works:
vMotion Migration is achieved by moving the memory state from one host
to another across the vMotion network which is private, non-routed, gigabit or
faster network connection between two hosts involved in the vMotion migration.
However, vMotion can be done only if certain requirements are met:
1. The hosts between which the vMotion need to be performed must have a shared
storage.
2. The participating hosts must have identical networks.
In
addition to that, requirements for VM are:
1. A virtual machine should not have connection to a virtual device with
a local image mounted.
2. A virtual machine must not have connection to an internal
switch(vSwitch with zero uplinks)
3. A virtual machine must not have CPU affinity configured.
Moreover,
source and destination hosts must have:
1. Visibility to all storage (Fiber Channel, iSCSI or NAS) used by the
virtual machine.
2. At least a gigabit ethernet network
- Four concurrent vMotion migration on a 1 Gbps network
- Eight concurrent vMotion migration on a 10 Gbps network
3. Access to same physical network
4. Compatible CPUs
