I recently was tasked with managing a a few servers and one is particularly turning out to be difficult. I'm relatively new to managing server on Hyper-V and so I'm careful not to mess anything up. I have a Hyper-V VM and here are the properties
When I access the Virtual Hard Disks folder inside I see these:
My biggest problem is the host disk is full hence pauses the VM with the warning "Disk out of Space" but inside the VM I can see there;s plenty of space as below:
My thinking was, I take some space from the VM hard Disk and get it back to the Host. But the VM has checkpoints and when I access the Checkpoints tab to try and delete them, it tells me it cant because of multiple checkpoints.
Please help me figure out how I can approach this, while also shedding some more light on the matter.
File with ".avhdx" extension are differencing disks, i.e. they are based on a normal disk (".vhdx") and they only record the differences from the disk they are based on. They will grow larger over time, as more disk changes happen (it looks like yours have been active for two years).
Differencing disks are usually created during checkpoints, and they are automatically deleted when checkpoints are removed. If a VM has multiple checkpoints, each one will create a new ".avhdx" file for each disk, recording the changes from the previous one.
You should delete the VM checkpoints; this will merge the differencing disks back into the main disks and remove the .avhdx files. You should NOT delete them manually.
Documentation here: https://learn.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/checkpoints.
Edit:
To see and manage (create/remove/delete) checkpoints, you have to do it from the main Hyper-V Manager console, not from the VM settings; see image below.
You need to add hard drive storage to the host, and move some of the VM guest(s) to it. Also review the checkpoints for appropriateness.