Jump to content
RESET Forums (homeservershow.com)

ESXi - Slow data transfer


Recommended Posts

I'm hoping somebody can help before i put my n54l through a window.

Here’s where I'm at. I've had it a good 6 months now, W7 installed plodding along running Plex Media Sever no problems. I'm now setting up my own home lab to start studying for my MCSE 2012.

I P2V my image of W7 and stored it on my laptop. I then installed ESXi 5.1 to my internal USB drive on my n54l, converted my image of W7 to run on ESXi, sorted. All works as it should.

Now i have a 1TB FAT32 drive with all my media on, i bought another 1TB disk and created a datastore and added it to my W7 VM. All good. VM running fine, new disk sat waiting for my data to come over.

Now i need to get my data from my full TB disk to the nearly created disk on my W7 VM..This is where I'm getting problems.

I've tried to RDM the disk but it wouldn’t play, i don’t remember the error exactly but it said something about the disk not supporting large files. I'm assuming its because the disk is FAT32?

I've added the disk to an external enclosure and connected it to the VM. The transfer rate is so painfully slow I've tried other external disks and it’s the same.

I've also noticed that copying data on this VM isnt the best either, it starts off at a normal transfer rate than gradually gets slower and slower.

Does anyone have any ideas what the problem could be, do you think the image could just be screwed up from the P2V?

What is going to be the best way to transfer over my data?


What type of speeds should you be seeing transfer from drive to drive etc?

Cheers smile.gif


Link to comment
Share on other sites

I started to build this media drive up some time ago, and when i realised it was FAT32 i had gone past the point of no return and just carried on with it.


I've come to the conclusion this data is going to take a year to move. But i was wondering. What speeds should you be seeing transfer data from 1 drive to another, both within the same VM but both on different datastores?



Link to comment
Share on other sites

  • 3 weeks later...

I don't quite understand what you've done but let me take a shot at this.


You P2V the Win7 from the HP box to your laptop, which is probably running VMware Workstation? Then you made it ESXi compatible and moved it onto the one disk you added to the HP box and formatted as a VMFS datastore?


So now you have a 1 TB VMFS datastore with one Win7 VM running fine, and now you want to move your other data. Am I on the right track?


Does the VM use the entire datastore? Did you create a virtual hard drive and assign to the Win7 VM?


Here are some important notes about datastores and vmdk sizes. The default 1 MB setting allows for VMDKs up to 256 GB, 2 MB = 512 GB, etc.


You cannot add RDM that is mounted as a SATA drive. Only FC or iSCSI LUNs. There is a hack for this to make SATA work (Google it)

You cannot pass-through USB to ESXi unless your motherboard BIOS supports direct access pass through.


If your VM is 100 GB or 200 GB, then create multiple VMDKs of 250 GB or smaller and make them dynamic disks in Win7 and span them for a large volume. Then copy your data within Windows. Since you already created the datastore the only way to change the supported VMDK size is to delete and recreate the datastore with the right settings for the VDMK size you want.  That means moving your VM so that it is safe on some other drive first.


Then use the laptop to mount the data drive in a USB enclosure (FAT 32) and copy over via the network.


Hope this helps.


Also, note that ESXi 5.x and SATA don't work all that fast. The drivers are not optimized for SATA drives. Even iSCSI isn't all that fast on ESXi 5.x.

For the home user the better option is a Win7 or Win8 PC with lots of memory and fast drives running VMware Workstation or Player. The Windows disk driver is optimized for SATA. Much faster.

Edited by dj-h-
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...