# Account for fault-domain alignment when reattaching Premium SSD v2 disks

> Why can repeated disk moves fail while Azure is aligning Premium SSD v2 storage with an availability-set VM?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260909-096-account-for-fault-domain-alignment-when-reattaching-premium-ssd-v2-disks/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-10T00:30:20+00:00
- Modified: 2026-09-10T00:35:08+00:00
- Last reviewed by DSE: 2026-09-09
- Resource type: Guide
- DSE priority: Information
- Topics: IT, Networks & Infrastructure
- Reading time: 2 minutes

## What you need to know

Why can repeated disk moves fail while Azure is aligning Premium SSD v2 storage with an availability-set VM?

## Potentially affected

Premium SSD v2 availability-set deployments in the supported regions without availability zones, with the required feature registered.

## DSE recommendation

Review fault-domain copy status before repeated reattachment, expansion, or customer-managed-key changes.

## Article

## Source facts

In supported nonzonal regions, attaching a Premium SSD v2 disk across fault domains can trigger a background move to align storage with the VM. Only one copy can run per disk; reattachment, expansion, and customer-managed-key changes face documented restrictions during alignment. OptimizedForFrequentAttach skips alignment copies on future attachments. Changing that property on an attached disk first requires detaching it. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/virtual-machines/use-premium-ssd-v2-with-availability-set).

## Applicability

Confirm regional eligibility and required subscription registration before reviewing this behavior. Identify the disk, destination VM, availability set, and any copy already underway. Distinguish a fault-domain alignment copy from background creation from a snapshot; check the applicable restriction before retrying an operation.

## DSE recommendation

Review fault-domain copy status before repeated reattachment, expansion, or customer-managed-key changes. For workloads that frequently move disks, have the storage and availability owners decide whether skipping future alignment is acceptable. Document that decision as a change in alignment behavior, not a switch that merely makes the same placement finish faster. Schedule any necessary detachment with the application owner.

## Verification

Observe a controlled attachment and reconcile the resulting copy state with the requested follow-up operation. For an approved frequent-attach design, verify the disk property and actual subsequent behavior on a test workload. Preserve disk and VM identifiers, fault-domain context, and measured outcomes. Avoid repeated detach/attach attempts while the documented copy restriction remains unresolved, and confirm application recovery after the authorized move.

## Official references

[Microsoft Learn: Premium SSD v2 with availability-set VMs](https://learn.microsoft.com/en-us/azure/virtual-machines/use-premium-ssd-v2-with-availability-set). Source reviewed September 9, 2026.

## Primary reference

- Name: Use Premium SSD v2 with VMs in availability set - Azure Virtual Machines | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/virtual-machines/use-premium-ssd-v2-with-availability-set
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Account for fault-domain alignment when reattaching Premium SSD v2 disks,” DSE Security, https://update.dsesecurity.com/updates/dse-20260909-096-account-for-fault-domain-alignment-when-reattaching-premium-ssd-v2-disks/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
Copyright © 2026 Detection Systems & Engineering. All rights reserved.