Considerations and Limitations for Restore to Microsoft Azure

When planning to restore workloads to Microsoft Azure, consider the following general limitations:

  • Veeam Backup & Replication supports restore to Microsoft Azure for the following workloads:
    • Microsoft Windows workloads that run Windows Server 2008/Windows Vista and later.
    • Linux workloads (see the Supported Distributions & Versions section in Microsoft Docs).

Important

We strongly recommend having dracut and mkinitrd installed on Linux machines that will be restored to Azure. Otherwise, they may not boot after restore.

  • If you use a cloud-init-based Linux distribution, we recommend that you use SSH keys on these distributions. If you use a password, it is blocked after restore for security reasons. To reset the password on the restored VM, you need to use the VMAccess extension. For more information, see Microsoft Docs.
  • During restore, Veeam Backup & Replication uses Azure Blob SAS links to the target VM disks. That is why DNS must resolve these Azure Blob endpoints and the firewall rules must allow such traffic.
  • When you select a storage account whose resources you want to use to store disks of the restored workload, consider the following:
  • Storage accounts with the zone-redundant storage (ZRS), geo-zone-redundant storage (GZRS) and geo-redundant storage (GRS) replication options are not supported. However, read-access geo-redundant storage (RA-GRS) option is supported. For details on replication options, see Microsoft Docs.
  • If you plan to use a premium storage account and want to store unmanaged disks there, the restore speed for such disks will be limited to 30 MB/s (approximately).

For the full list of access-restricted regions, see Microsoft Docs. The regions are marked with an asterisk *.

  • [Azure VMs] Microsoft has strict rules for naming Azure resources. For naming rules that your VM names must correspond to, see Microsoft Docs: the Resource name rules and Resolve errors for reserved resource names articles.
  • [Azure VMs] Veeam Backup & Replication does not support restore of Azure Ultra Disks.
  • [Azure VMs] Consider the following limitations for disk sizes:
  • [Unmanaged VM disks] Veeam Backup & Replication supports restoring of disks equal to or less than 4093 GB. This is due to the following reasons: VM disks can increase in size up to 2 GB because of conversion during the restore process; Azure supports disk up to 4095 GB. For more information on all disk sizes that Azure supports, see Microsoft Docs.
  • [Managed VM disks] Veeam Backup & Replication supports restoring disks equal or less than 4093 GB for OS disks and equal to or less than 32765 GB for other disks. During the restore process, VM disks can increase in size up to 2 GB because of conversion. For more information on all managed disk sizes that Azure supports, see Microsoft Docs. For more information on OS disk size that Azure supports, see Microsoft Docs. Note that supported disk sizes for Azure and Veeam Backup & Replication differ.

Important

The price of a restored VM disk can become higher because of the increase in disk size during the restore process. For more information on pricing, see Managed Disks pricing and Unmanaged Disk and Page Blob pricing.

  • [Azure Stack VMs] Veeam Backup & Replication supports restoring of managed and unmanaged disks equal to or less than 1021 GB. This is due to the following reasons: VM disks can increase in size up to 2 GB because of conversion during the restore process; Azure Stack supports disk up to 1023 GB. For more information on all disk sizes that Azure supports, see Microsoft Docs.

You can change the maximum supported size for unmanaged VM disks with a registry value. For more information, contact Veeam Customer Support.

Important

The price of a restored VM disk can become higher because of the increase in disk size during the restore process. For more information on pricing, see Azure Stack Hub Pricing.

  • If the system disk of an initial workload uses the GPT partitioning scheme, the number of partitions on the disk cannot exceed 4. During restore such disk will be converted to a disk with the MBR partitioning scheme.
  • Veeam Backup & Replication does not support restoring of disks whose logical sector size is 4096 bytes. Contents of such disks will be unreadable in Microsoft Azure.
  • The restore to Microsoft Azure functionality does not support the Azure Hybrid Use Benefit program.
  • [For restore from backups created by Veeam Agent for Microsoft Windows] Workloads from a backup that contains a failover cluster are restored as separate VMs, not as a cluster. Shared cluster disks of these VMs are restored as regular disks.

Requirements and Limitations for Generation 2 VM Support

Before enabling Generation 2 VM support, consider the following requirements and limitations:

  • When you select VM sizes at the Specify VM Size step of the Restore to Azure wizard, make sure that the selected size is compatible with Generation 2 VMs.
  • Generation 2 VMs support only managed disks. Thus, you will need to select the managed storage type from the Storage type list at the Specify VM Size step of the Restore to Azure wizard.
  • Make sure that OSes of backed-up workloads that you plan to restore have UEFI boot. Otherwise, the restored VMs may be unbootable.

Page updated 1/11/2024

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