vMotion Flashcards
(53 cards)
What does vMotion allow you to do?
vMotion allows you to move a vm from one host to another without downtime
What components does vMotion Transfer via a high speed/low latency network connection?
a vm’s active memory and execution state
How fast is vMotion with a gigabit ethernet network?
It is 2 seconds or less
What can you use vMotion for?
- optimize resource pools
- hardware maintenance
- respond to host failures
What has to be migrated with a VM?
- processor and device state (CPU, network, SVGA, etc)
- VM disks
- Memory
- Shared storage connection between a source and destination host
- a vMotion network
True or False: Guest OS know when they are vMotioned
False
True or False: vMotion can not be used for load balancing purposes
False
What other vSphere software features utilize vMotion?
- Distributed Resource Scheduler (DRS)
- Distributed Power Management
- Fault Tolerance
What are the steps to vMotion a VM?
- right click a VM
- select “migrate”
- change the compute resource
- select target host
- select vMotion network
- select vMotion priority level
How many steps are involved in the vMotion process?
13
0-12 (including zero)
What vSphere components are involved in the vMotion process?
- VPXD
- VPXA
- hostd
- VMX
- VMM
- VM kernel migration module
- source host
- destination host
- vCenter
- migration spec
- compatibility check
What is the “migration specification” created by vCenter when a vMotion is initiated?
It is an array package of the migration specifications needed to vMotion a VM such as:
- configuration of the target VM
- source host information
- destination host information
- vMotion network details of target VM
Who does vCenter share the “migration specification” with?
the source and destination hosts in the vMotion exchange
What vCenter service forwards the “migration specification” to the source and destination host in a vMotion exchange?
vxpd
How does VXPD forward vCenter information to hosts?
By calling to the VPXA service that resides on ESXi hosts
What happens after the VXPA service receives the “migration specification” from the VXPD service?
It forwards the “migration specification” to the hostd service on the ESXi host
What action does hostd make to ensure that a VM’s configuration does not change during a vMotion?
It places the host in an intermediate state (disk lock)
After hostd places a VM in an intermediate state, what happens?
Hostd calls to the VMM and VMX service on the destination host so that VMM will transfer the VM’s storage and network I/O requests to the VM’s vmkernel. And, so that the VMX (vm extenstion) service will manage and sustain non critical I/O requests associated with the VM
What does the VMM service stand for?
VM monitor service
What does the VMX service stand for?
The VM extension service
What happens when VMM and VMX receive all of the data forwarded from the hostd service?
Both services call to the VMkernel migrate module on the destination host and the VMkernel migrate module opens sockets on the source host for the vMotion network. In addition, the module starts a handshake request process with the destination host’s VMkernel migrate module
What happens after the source host’s VMkernel migration module performs a successful handshake with the VMkernel migration module on the destination host?
it forward’s the “migration specification” to the destination host’s VMkernel migration module and the destination’s VMkernel migration module makes a call to the VMX service on the destination host
What is the role of the VMX service on the destination host?
When it receives the “migration specification” from the VMkernel migration module, it passes the specification to the hostd service. The hostd service then passes the specification to the destination host’s VPXA service. The VPXA service then passes the specification to the VPXD service on the vCenter.
True or False: When a vm is placed in an intermediate state, its configurations cannot be changed
True
