I built a new Windows 2019 Server VM the other day on our ESXi platform. I’ll migrate some services currently running on a Windows 2008R2 Server over, then decommission the old VM. One of the challenges I faced was getting our corporate image, which is stored as an image file in Phoenix, Arizona. Because of the way our storage is setup, I couldn’t directly transfer it to our storage system.

I downloaded the VMDK file to my laptop first. ESXi had to expand the file from 24GB to the full 80GB during the download, which took an hour or so. Next, I uploaded the 80GB VMDK file to our local ESXi cluster. A couple of hours later, it was finished!

I attached it to a new VM, and then did a storage vMotion. Fortunately, I have a couple of datastores to choose from!

1. Right-click the virtual machine and select Migrate.
2. In Step 1 of the Wizard (Select a Migration Type), select Change Storage Only and click Next. We don’t need to move the VM to a new host, only the files.
3. In Step 2 of the Wizard (Select Storage) select the option Configure Per Disk in the upper right.
4. Select the disk to modify.
5. Under Storage category, select the destination datastore. Under the Disk Format option select Thin Provision, and click Next.
6. In Step 3 of the Wizard (Ready to Complete), review the information and click Finish.

References

Changing the thick or thin provisioning of a virtual disk (2014832)