REFS Allocation unit size for a volume containing virtual VHDX disks?

Ace-IT used Ask the Experts™
To store VHDX vdisks, with NTFS, we’d use 64k but I’ve heard that 4k is recommended with REFS.
Is 4k actually correct to store VHDX on refs?
Watch Question

Do more with

Expert Office
EXPERT OFFICE® is a registered trademark of EXPERTS EXCHANGE®
Technical Architect - HA/Compute/Storage
Just create the volume either in Server Manager or PowerShell and leave the defaults. Storage Spaces will know what to do with the setup.

We change the Interleave (storage block size) when 64KB is required for storing Veeam backups. There are other reasons to do so but that's for another conversation.

4KB is too small. Period.


I guess this brings me to ask if I should be using REFS for Server 2019 Hyper-v or NTFS.  I'll post that under a new topic.
Philip ElderTechnical Architect - HA/Compute/Storage

Standalone? No. Use NTFS.

ReFS is sanctioned on Storage Spaces and Storage Spaces Direct for workloads. SAN only for archival storage.

Do more with

Expert Office
Submit tech questions to Ask the Experts™ at any time to receive solutions, advice, and new ideas from leading industry professionals.

Start 7-Day Free Trial