Cold migration using vMotion between datastores

[thomps01]

To complete a cold migration between 2 ESX servers do the source and destination ESX hosts need to see both datastores?

I have an ESX 3.5 host with 1 datastore called data01 and an ESXi 5.0 host with a datastore called data02. Using vCenter to manage both ESX hosts I want to power off a VM running on the 3.5 host and perform a cold migration including a datastore move to the 5.0 host.

Can this be achieved?

I'm unable to zone the storage presented to the ESX 3.5 host to the 5.0 host and also unable to present the 5.0 storage to the 3.5 host.

[Troy_Clavell]

you should have no problem if doing a cold migration.

[Virtualinfra]

Storage should be shared across both the host for storage vmotion - this is mandatory.

But in my experience i was able to present a shared lun between esx 3.5 update 5 to esxi 4.1 u2. Never tried with esxi 5

Your might be facing the problem of unable to present the storage of esx 3.5 to esxi 5 and vice versa because the LUN recogniation are changed from esx(i) 4.X

refer the below link

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=101495...

Award point by clicking the below tab if the answer is helpful or correct.

[Troy_Clavell · Accepted solution]

The OP is talking about a cold migration.  In the scenario outlined, there does not have to be shared storage.  As long as the cold migration stays within the same vCenter instance, there should be no issues.

[thomps01]

This is most interesting because both hosts will be managed from the same vCenter but not share storage.

So in theory, it's possible to migrate a VM from local storage on an ESX host which doesn't have any SAN connectivity across to an ESX host which has storage presented from a SAN.

[Virtualinfra]

Thanks for the update, but as per the storage vMotion requirements and limitations its mentioned that the host should have access to both source and target refer below

http://pubs.vmware.com/vsphere-50/index.jsp?topic=/com.vmware.vsphere.introduction.doc_50/GUID-F7A7E...

" I agree we have option called change host and datastore but still the host performing migration should have access to both source and target" to confirm, i am currently not able to access my labs.. Please correct me.

***Also with ESX 3.5 there is a limitation that migration with host and datastore at time cant be carried. Please correct me if i am wrong.I am not sure about this****

Note:

Storage vMotion Requirements and Limitations

A virtual machine and its host must meet resource and configuration requirements for the virtual machine disks to be migrated with Storage vMotion.

Storage vMotion is subject to the following requirements and limitations:

■	Virtual machine disks must be in persistent mode or be raw device mappings (RDMs). For virtual compatibility mode RDMs, you can migrate the mapping file or convert to thick-provisioned or thin-provisioned disks during migration as long as the destination is not an NFS datastore. If you convert the mapping file, a new virtual disk is created and the contents of the mapped LUN are copied to this disk. For physical compatibility mode RDMs, you can migrate the mapping file only.
■	Migration of virtual machines during VMware Tools installation is not supported.
■	The host on which the virtual machine is running must have a license that includes Storage vMotion.
■	ESX/ESXi 3.5 hosts must be licensed and configured for vMotion. ESX/ESXi 4.0 and later hosts do not require vMotion configuration in order to perform migration with Storage vMotion.
■	The host on which the virtual machine is running must have access to both the source and target datastores.
■	For limits on the number of simultaneous migrations with vMotion and Storage vMotion, see Limits on Simultaneous Migrations.

Thanks...

[Troy_Clavell]

thomps01 wrote:

This is most interesting because both hosts will be managed from the same vCenter but not share storage.

So in theory, it's possible to migrate a VM from local storage on an ESX host which doesn't have any SAN connectivity across to an ESX host which has storage presented from a SAN.

yes, this is a reality ONLY if the VM is powered off.  If you are talking about live migrations it's a whole different conversation.

So, from my understanding, you are wanting to MOVE the VM from one host to another while the guest is in a Powered OFF state.  When the guest is powered off you can freely move around the virtual infrastructure.

[Troy_Clavell]

Dharshan wrote:

Thanks for the update, but as per the storage vMotion requirements and limitations its mentioned that the host should have access to both source and target

again, we are NOT talking about Storage vMotion.  We are talking about a move while the VM is powered off.

[a_p_]

Troy is correct, for cold migration there's no requirement for shared storage.

from Cold Migration

Cold migration is the migration of a powered-off virtual machine. With cold migration,  you have the option of moving the associated disks from one datastore  to another. The virtual machines are not required to be on shared  storage.

André

[thomps01]

Thank you for your assistance with this, it's made my life much easier.

Knowing that I can easily move virtual machines from 3.5 hosts and datastores to 5.0 hosts and datastores without having to re-zone or present any new storage is good news.

I completly understand that the storage vMotion requirements are different and will need a host to see both source and destination LUNs, but that's not what I'm doing here.

Thanks all

[Virtualinfra]

Thanks Troy Clavell...

[admin]

What you can do is after powering off the machine u can clone it and put the machine in datasore 2 attached to the Host with 5.0