Change the size of a virtual machine
Applies to: ✔️ Linux VMs ✔️ Windows VMs ✔️ Flexible scale sets
This article shows you how to change an existing virtual machine's VM size.
After you create a virtual machine (VM), you can scale the VM up or down by changing the VM size. In some cases, you must deallocate the VM first. Deallocation may be necessary if the new size isn't available on the same hardware cluster that is currently hosting the VM.
If your VM uses Premium Storage, make sure that you choose an s version of the size to get Premium Storage support. For example, choose Standard_E4s_v3 instead of Standard_E4_v3.
Change the VM size
- Open the Azure portal.
- Open the page for the virtual machine.
- In the left menu, select Size.
- Pick a new size from the list of available sizes and then select Resize.
If the virtual machine is currently running, changing its size will cause it to restart.
If your VM is still running and you don't see the size you want in the list, stopping the virtual machine may reveal more sizes.
Deallocating the VM also releases any dynamic IP addresses assigned to the VM. The OS and data disks are not affected.
If you are resizing a production VM, consider using Azure Capacity Reservations to reserve Compute capacity in the region.
Choose the right SKU
When resizing a VM, it's important to choose the right SKU based on the signals from the VM to determine whether you need more CPU, memory, or storage capacity:
- If the VM is running a CPU-intensive workload, such as a database server or a web server with high traffic, you may need to choose a SKU with more CPU cores.
- If the VM is running a memory-intensive workload, such as a machine learning model or a big data application, you may need to choose a SKU with more memory.
- If the VM is running out of storage capacity, you may need to choose a SKU with more storage.
For more information on choosing the right SKU, you can use the following resources:
- Sizes for VMs in Azure: This article lists all the VM sizes available in Azure.
- Azure VM Selector: This tool helps you find the right VM SKU based on your workload type, OS and software, and deployment region.
You can't resize a VM size that has a local temp disk to a VM size with no local temp disk and vice versa.
The only combinations allowed for resizing are:
- VM (with local temp disk) -> VM (with local temp disk); and
- VM (with no local temp disk) -> VM (with no local temp disk).
For a work-around, see How do I migrate from a VM size with local temp disk to a VM size with no local temp disk? . The work-around can be used to resize a VM with no local temp disk to VM with a local temp disk. You create a snapshot of the VM with no local temp disk > create a disk from the snapshot > create VM from the disk with appropriate VM size that supports VMs with a local temp disk.
- For more scalability, run multiple VM instances and scale out.
- For more SKU selection information, see Sizes for virtual machines in Azure.
- To determine VM sizes by workload type, OS and software, or deployment region, see Azure VM Selector.
- For more information on Virtual Machine Scale Sets (VMSS) sizes, see Automatically scale machines in a VMSS.
- For more cost management planning information, see the Plan and manage your Azure costs module.