Why do we want to connect hyper-v vm to a physical hard drive?

I'm new to this job.
We have a file server with all network shared drives. That server is a vm in a single hyper-v host with cluster. And the storage is local -- no SAN, etc.
I noticed this vm has two hard drives connected:
1. IDE Controller 0 : hard drive servername.vhdx
2. ScSI Controller:   Hard Drive: Physical drive Disk 6 7448.00 GB Bus 0 Lun 1 Target 0

Can you tell me if there is specific reason we want to connect to the physical hard drive instead of using virtual drives?
CastlewoodAsked:
Who is Participating?
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.

Dan LuteyCommented:
It was maybe added for more additional hard drive space. Is your local data store almost out of space? At the time it could of been the cheapest solution without buying a NAS or SAN.
Philip ElderTechnical Architect - HA/Compute/StorageCommented:
"single hyper-v host with cluster". That doesn't really make any sense?

Is the host standalone or a node in a Hyper-V cluster?

The 7TB drive is connected via USB and is being passed through to the guest VM?
Ross AlasCommented:
I'm not sure what version of Hyper-V you have but what you describe is called a pass-through disk.

If it's prior to 2012, VHDs had a limit of 2TB and you have almost 7.5 TB on  that which may be why.

In addition pass-through disks before had higher performance than virtual disks. Perhaps, it's to give the file server exclusive use of the hard disk.
HTML5 and CSS3 Fundamentals

Build a website from the ground up by first learning the fundamentals of HTML5 and CSS3, the two popular programming languages used to present content online. HTML deals with fonts, colors, graphics, and hyperlinks, while CSS describes how HTML elements are to be displayed.

CastlewoodAuthor Commented:
"with cluster" is a type. Sorry, should be "without cluster"
Ross, we are on 2012 R2 Hyper-V so 2T limit should not be the reason why we want to use 7.5T on pass-through. Since that particular vm is for network shared drives/files by whole company I guess could it be because pass-through to a physical hd is more flexible, speedy, and allowed bigger capacity??

Another question is, once that particular physical drive is used by a vm via pass-through, that drive can NOT be available as pass-through to other vm, correct?
Philip ElderTechnical Architect - HA/Compute/StorageCommented:
All of our standalone hosts are configured with two logical disks on one RAID 6 array:
+ LD0: 75GB Host OS
+ LD1: ???GB/??TB Data for VHDX and Config Files

We have standalone hosts with as little as 4 3.5" 15K SAS disks to 24 2.5" 10K or NearLine 7200 RPM disks.

In 2012 R2 pass-through is discouraged. Performance of VHDX on the above configured array with 8x 10K SAS in RAID 6 is about 800MB/Second and ~250-400 IOPS per disk depending on block size through the formatted stack.

How is that pass-through disk backed up?

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
Ross AlasCommented:
That right, a pass through disk can't be made available to another VM once assigned.

The performance of pass through disks vs using vhdx is negligble. It's less flexible since now you can't put other virtual disks on it.  

It was probably thought as a dedicated file storage and nothing else hence why it might have just been put as pass-through. There's really no other good reason to do otherwise.
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
Hyper-V

From novice to tech pro — start learning today.