Best way to migrate Data Disks between VMs without downtime

I would like to migrate two Hard Disks (main data disks)  from one VM to another without down time.
What is the best way to do this.

The existing server has  Windows 2012 R2  which has 1 OS Disk + 2 Hard Disks.
The Target (new) server has Windows 2012 R2 which has 1 OS Disk  only; and would like to migrate the  2 Hard DIsks from the existing server.
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
There are no features within VMware vSphere, which will allow you to do this with zero downtime.

You will need to use a Replication application  within the OS
cgeorgeisaacAuthor Commented:
Noted.   What are the options to do   with downtime.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Simplest option you've got Robcopy, you can keep both VMs up, and create a Sync/Mirror copy between the two servers, until the disk has been copied.

You could detach, and remove the disks from one VM, and add to the new VM, in realtime, HotPlug, VMs both can be powered up, you just need to make sure no-one is accessing them.

Are there shares on the source disk ?

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
The Five Tenets of the Most Secure Backup

Data loss can hit a business in any number of ways. In reality, companies should expect to lose data at some point. The challenge is having a plan to recover from such an event.

cgeorgeisaacAuthor Commented:
Yes there are shares on the source disks.
Instead of  Robcopy, will  creating a Clone in a different datastore  be another alternative?  However, not sure which will be faster RobCopy or Clone.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
but you want to MIGRATE, so why not detach and re-attach ?

no need to copy or clone ?

and quick!
cgeorgeisaacAuthor Commented:
Sounds good.  Will do.  (On another note:  Which is faster - RoboCopy or  Clone?) Thanks.
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Clone it's working at block, not file and folder level
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.