Azure backup restore extreme slow

Question

when i try to restore file and folder from Azure Backup, the virtual HDD is take most one hours to ready, and last month just need 3 minute to ready.

is Azure server trouble recently?

Answer 1

The slow performance you are experiencing during the restore process from Azure Backup could be due to several factors. Here are some potential causes:

1. Performance Bottlenecks: There may be performance bottlenecks on the computer or virtual machine from which you are restoring. This can include issues with disk read/write speeds or available network bandwidth.
2. Large Volume of Data: If you are restoring a large number of files or folders, especially if they are numerous small files, this can significantly increase the time required for the restore operation. Azure Backup may take longer to catalog and transfer these files.
3. Concurrent Processes: If other processes or backup jobs are running simultaneously, they can interfere with the restore process, leading to delays.
4. Azure Service Issues: While it is possible that there could be temporary issues with Azure services affecting performance, you may want to check Azure service health for any ongoing incidents.

To troubleshoot further, consider checking the performance metrics on your system and ensuring that no other heavy processes are running during the restore. Additionally, reviewing the logs for any specific errors or delays can provide more insight into the issue.

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References:

• Troubleshoot slow backup of files and folders in Azure Backup
• Troubleshoot the Microsoft Azure Recovery Services (MARS) agent

Answer 2

Hello Wong Koon Sian

Thank you for posting your query on Microsoft Q&A platform.
Azure Backup file restore is extremely slow, the virtual HDD/iSCSI mount now takes almost 1 hour than 3 minutes previously might be due to below following reasons:

• Restoring from vault tier instead of snapshot (Instant Restore) → slower iSCSI staging/mount.
• Microsoft iSCSI Initiator driver/service not healthy on the recovery machine.
• Default recovery timeout too low for large recovery points.
• AV/process load or heavy I/O interference.

You can try below following resolution steps as per the method you are trying to restore file/folder from azure backup:

A) MARS Agent – File & Folder Recovery (on‑prem/VM with MARS)

1. Prefer snapshot‑backed recovery points (Instant Restore) for fast mounts.
2. Update to the latest MARS agent.
3. Validate/repair Microsoft iSCSI Initiator (Device Manager), then restart the service.
4. Extend recovery timeout for large restores via registry:

HKLM\SOFTWARE\Microsoft\Windows Azure Backup\Config\CloudBackupProvider
DWORD: RecoveryJobTimeOut = <hours>  (e.g., 12)

B) Azure IaaS VM Backup – File‑level Restore (mount disk from VM backup)

1. Choose a snapshot recovery point (Instant Restore) when available.
2. Ensure the VM has the latest Azure Backup extension.
3. Restore from a VM in the same region as the vault; reduce competing I/O.
4. Apply AV exclusions on temporary mount paths, detach the disk after copying.

Verify service health: Check your subscription’s Azure Service Health for any Backup/Recovery advisories affecting your region.

Kindly let us know if the solution provided worked for you. If you need any further assistance, please feel free to reach out.

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Thanks,

Suchitra.