Archive Azure VM disk on Blob storage

Question

Hi ,

I have an Azure VM with several attached disks with big size more than 12TiB. The VM is currently deallocated and data on disk is not often accessed. Since the VM disk cost is quite high, I'm thinking to store those VM disks to Azure storage with archive tier to save cost.

I do calculation on the cost archiving those disk on Azure storage versus current cost and would like to have further advice if possible.

Current VM disk cost: ~CAD 1,000 / month

• Azure storage cost (archive tier $0.00136 per GB): CAD 16.62 / month
• Date write cost: CAD 0 (free)
• Index (GB/month): NA
• Read/Write operation: Not included, plan to keep archive data there for the next 5 years.

Any potential cost besides above?

Thanks in advance.

Answer 1

Managed disks and page blobs do not support access tiers - only block blobs do.

https://learn.microsoft.com/en-us/azure/storage/blobs/access-tiers-overview

Consider backing up the disks and deleting them.

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hth

Marcin

Answer 2

Hello Marcin Policht,

Thank you for posting your query here!

Adding on to the previous response, since you cannot directly transfer Managed Disks or page blobs to an archive tier, you would need to convert these disks into a format suitable for block blobs if you want to use the archive tier. Here's how you might approach it:

· Create a snapshot of your Managed Disk. This snapshot captures the disk state at a specific point in time. https://learn.microsoft.com/en-us/azure/virtual-machines/snapshot-copy-managed-disk?tabs=portal

· Once the snapshot is created, you can export it to a VHD file. This is done by copying the snapshot to a Blob Storage account as a page blob (VHD). https://learn.microsoft.com/en-us/azure/virtual-machines/scripts/copy-snapshot-to-storage-account

· Once your VHD is in Blob Storage as a page blob, you might want to convert it into a block blob to enable setting an access tier like 'Archive'. https://learn.microsoft.com/en-us/azure/storage/blobs/convert-append-and-page-blobs-to-block-blobs?tabs=azcopy

· Finally, you can set the access tier to 'Cool' or 'Archive' depending on how frequently you expect to access the VHD. Set a blob's access tier - Azure Storage | Microsoft Learn

Do let us know if you have any further queries. I’m happy to assist you further.

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