How to increase VM hard disk
VMware is a widely used enterprise virtualization platform, and Avanetco uses it as well. A basic question for junior admins is how to increase VM hard disk size or troubleshoot its errors.
Before you increase a VM hard disk, there are some things to check. When you first create a VM, you are asked for the type of hard disk, and the process differs based on that type. There are two types of disks:
- Thin provision: if you chose this type, you can easily increase the VM hard disk while the virtual machine is powered on.
- Thick provision: if you chose this type, you can’t increase the VM size with the method above. You need to migrate the VM first. During migration you are asked to choose the disk type again; choose thin provision this time, and then you can follow the steps to increase the VM hard disk.
Migration is a complicated task, so we will cover it in another article. Here we look at the scenario where you have a thin-provisioned hard disk that can be expanded.
Note that you should remove all snapshots first.
Log in to the vCenter or ESXi server that hosts the VM, right-click the VM, select Edit Settings and choose the hard disk you want to increase:
Expand that disk’s menu and enter the new capacity.
Because the VM was powered on, the OS might not detect the change. In Windows, you can follow the steps below. Linux needs some reconfiguration, so we will cover it in another post.
In Windows, open Disk Management and click Rescan Disks.
