Requirements for Microsoft Azure Environments
■ Azure ZCA can be installed only on Windows Server 2012 R2 and higher.
■ Only virtual machines that are supported by Azure can be protected by Zerto Virtual Replication. All Windows operating systems are supported.
Note: Microsoft does not support operating systems that are past the
End of Support date, without a
Custom Support Agreement (CSA). For more information about Microsoft operating systems support for Microsoft Azure, refer to
https://support.microsoft.com/en-us/kb/2721672.
■ To replicate between Azure and your site, you must have a virtual machine in Azure with a Zerto Cloud Appliance installed on it. This ZCA must be paired with your site.
■ Only general-purpose v1 (GPv1) accounts are supported.
■ It is recommended to use a separate storage account for each ZCA.
■ For Linux distribution, refer to Azure documentation:
Requirements for Replication From Azure
■ For Virtual Machines to be protected from Azure, the VM volumes must reside in the Standard storage account defined during ZCA installation.
A Standard storage account is created or selected upon ZCA installation.
■ Type: Standard storage
■ Recovery and journal volumes reside on this Zerto Storage Account.
■ Only general-purpose v1 (GPv1) accounts are supported.
■ Azure VMs with all disks on this Zerto Storage Account can be protected by Zerto.
■ Blob Storage is not supported.
■ VMs which are not deployed via the Azure Resource Manager cannot be protected from Azure.
Requirements for Replication To Azure
■ Protected volumes are recovered in Azure as VHD disks in a page blob. Virtual machines with disks that are less than 1GB are recovered with disks of 1GB.
Note: For some instance sizes, the Azure virtual machine is created with a Local SSD disk which is a temporary disk. This disk is in addition to the disks associated with each protected virtual machine.
■ The following limitations apply when protecting to Azure
■ Virtual machines with UEFI Firmware cannot be protected.
■ You cannot protect machines that have a disk larger than 4 TB.
■ The protected virtual machines needs to have at least one NIC.
■ Reserve at least 2 CPUs and 4GB RAM for the machine using a subnet accessible by other Zerto Virtual Replication sites.
■ The supported number of data disks and NICS per virtual machine is dependent on the selected instance size. For example, instance size D3_v2 allows up to eight data disks per virtual machine.
Requirements for Replication within Azure
■ Azure ZCA on both Azure sites need to be version 6.0 and higher.
■ The following limitations apply when protecting within Azure:
■ Self replication is not supported.
Additional Azure Considerations
For additional considerations, see
Azure subscription and service limits, quotas and constraints:
https://docs.microsoft.com/en-us/azure/azure-subscription-service-limits.For example from the link, see the following default values:
■ There can be multiple Zerto Cloud Appliances per Azure subscription and region.
■ 20 cores per subscription
■ 200 Storage accounts per subscription
■ 20 VMs per region per subscription
■ 20 VMs per series (Dv2, F, etc.) cores per subscription per Region
Additionally, see the following example for maximum values:
■ A Standard storage account has a maximum total request rate of 20,000 IOPS. The total IOPS across all of your virtual machine disks in a Standard storage account should not exceed this limit.
VM Tier | Basic Tier VM | Standard Tier VM |
Disk size | 4 TB | 4 TB |
Max 8 KB IOPS per persistent disk | 300 | 500 |
Max number of disks performing max IOPS | 66 | 50 |
Azure Limitations Which Affect Installation and Recoverability
Below are the default Azure limitations which affect installation and recovery.
Default Azure limitations which Affect Installation
■ Storage Limitations:
■ Number of storage accounts: 200 per subscription (note: max is 250)
Default Azure Limitations which Affect Recovery
Virtual Machines Limitations | VMs per subscription per region: | 20 (max: 10K) |
VM total cores per subscription per region: | 20 |
Instance sizes: | Limited per region. Many of them are 20 cores per region per subscription |
Resource groups per subscription: | 800 |
Networking | Network interfaces per region: | 350 |
NICs per instance: | Depends on instance size: |
Private IP Addresses per VNET per subscription per region: | 4096 |
Cloning of IP addresses during recovery operations: | Due to an Azure limitation, failing over Linux VMs with static IP is not supported. |
Storage | Storage account total size limitation: | 500 TB (# of entities (blobs, containers etc) within a storage account: unlimited) |
Max size of a page blob (vhd): | 4 TB |
Min size of a page blob (vhd): | 20 MB |
Max number of data disks: | Depends on instance size |
■