This article provides answers to frequently asked questions (FAQ) about Azure VM sizes that don't have a local temporary disk (that is, no local temp disk).
What does no local temp disk mean?
Traditionally, we have had VM sizes (for example, Standard_D2s_v3, Standard_E48_v3) that include a small local disk (that is, a D: Drive). With the VM series such as Dasv5 and Easv5 that small local disk no longer exists. However, you can still attach Standard HDD, Premium SSD or Ultra SSD to use as remote storage.
What if I still want a local temp disk?
If your workload requires a local temporary disk, we still offer sizes such as the Dadsv5.
Note
Local temporary disk isn't persistent; to ensure your data is persistent, please use Standard HDD, Premium SSD or Ultra SSD options.
Can I resize a VM size that has a local temp disk to a VM size with no local temp disk?
No. 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).
If interested in a work around, please see next question.
Note
If an image depends on the resource disk, or a pagefile or swapfile exists on the local temp disk, the diskless images won't work—instead, use the ‘with disk’ alternative.
How do I migrate from a VM size with local temp disk to a VM size with no local temp disk?
You can migrate by following these steps:
Connect to your Virtual Machine that has a local temporary disk (for example, a D: Drive) as a local admin.
Follow the guidelines on the "Temporarily move pagefile.sys to C drive" section of Use the D: drive as a data drive on a Windows VM to move the page file from the local temporary disk (D: drive) to the C: drive.
Note
Follow the guidelines on the "Temporarily move pagefile.sys to C drive" section of Use the D: drive as a data drive on a Windows VM to move page file from the local temporary disk (D: drive) to C: drive. Deviation from the steps outlined will lead to the error message - "Unable to resize the VM since changing from resource disk to non-resource disk VM size and vice-versa is not allowed.
Take a snapshot of the VM by following the steps outlined in Create a snapshot using the portal or Azure CLI.
Use snapshot to create a new diskless VM (such as, Dv5, Dsv5, Dasv5, Ev5, Esv5, Easv5 series) by following the steps outlined in Create a virtual machine from a snapshot with CLI.
Do these VM sizes support both Linux and Windows Operating Systems (OS)?
Yes.
Will this break my custom scripts, custom images or OS images that have scratch files or page files on a local temp disk?
If the custom OS image points to the local temp disk, the image might not work correctly with this diskless size.
Next steps
In this document, you learned more about the most frequent questions related to Azure VMs with no local temp disk. For more information about these VM sizes, see the following articles: