Adjustable storage repair speed in Azure Stack HCI and Windows Server

Applies to: Azure Stack HCI, version 21H2; Windows Server 2022

User adjustable storage repair speed is a new feature now available in preview that offers more control over the data resync process by allocating resources to either repair data copies (resiliency) or run active workloads (performance). This helps improve availability and allows you to service your clusters more flexibly and efficiently.

Storage repair speed settings

The storage speed repair settings are:

Setting Queue depth Resource allocation
Very low 1 Most resources to active workloads
Low 2 More resources to active workloads
Medium (default) 4 Balances workloads and repairs
High 8 More resources to resync and repairs
Very high 16 Most resources to resync and repairs

Very low to Low settings will allocate more resources to active workloads, allowing the server to complete mission-critical tasks. Take caution when changing the setting to Very low, as this may impact the time it takes for storage to regain full resiliency. High to Very high settings will prioritize storage resync and repairs, allowing a patch and update cycle to complete faster. The default setting is Medium, which ensures a balance of workload and repair prioritization. It's recommended to keep the repair speed set to Medium in most cases, unless you have a good reason for prioritizing either resiliency or performance.

Important

When storage repair speed is set to Very high, active workloads and cluster performance can be impacted. Likewise, when repair speed is set to Very low, it will take more time for storage to regain full resiliency.

Change storage repair speed using Windows Admin Center

To change the storage repair speed for a cluster by using Windows Admin Center:

You can change storage repair speeds in Cluster Manager > Settings > Storage Spaces and pools

  1. In Cluster Manager, select Settings from the lower left.
  2. In the Settings pane, select Storage Spaces and pools.
  3. Use the Storage repair speed dropdown to select the desired speed.
  4. Optional: Review the caution text if selecting Very low or Very high.
  5. Select Save.

Change storage repair speed using PowerShell:

To check the current repair speed setting:

Get-StorageSubSystem -FriendlyName <name of cluster subsystem> | ft FriendlyName,VirtualDiskRepairQueueDepth

To set the repair speed:

Set-StorageSubSystem -FriendlyName <name of cluster subsystem> -VirtualDiskRepairQueueDepth <value>

Next steps

For more information, see also: