Adding Virtual Machines to a VPG

Managing VPGs : Adding Virtual Machines to a VPG - Overview

Adding Virtual Machines to a VPG - Overview

You can add virtual machines that are not already included in a VPG, to an existing VPG. A virtual machine can be protected in a maximum of three existing VPGs, provided that the VPGs are recovered to different sites.

■ Protecting virtual machines in several VPGs is enabled only if both the protected site and the recovery site, as well as the VRAs installed on these sites, are of version 5.0 and higher.

■ You cannot add a virtual machine in an existing VPG, while a retention process is running.

■ Only virtual machines with a maximum of 60 disks can be protected.

■ 60 disks requires 4 SCSI controllers each with a maximum of 15 disks.

For AWS or Azure recovery sites, see the following topics, then continue with How to Add Virtual Machines to an Existing VPG.

Adding Virtual Machines to a VPG - When the Recovery Site is AWS

Adding Virtual Machines to a VPG - When the Recovery Site is Azure

Adding Virtual Machines to a VPG - When the Recovery Site is AWS

■ Only virtual machines that are supported by AWS can be protected by Zerto. Refer to AWS documentation for the supported operating systems.

■ A VPC must exist, and a security group and subnet must be assigned to it and to all other VPCs you want to use for recovered virtual machines.

■ AWS allocates EBS volumes by multiplications 1 GiB. When recovering VMs to AWS, whose volume sizes are not multiplications of GiB, AWS rounds the recovered volumes to the closest GiB, resulting in a size mismatch between the recovered and protected volumes. In this case, the original protected disks cannot be used for preseed and the VMs are recovered in Needs Configuration state.

■ The following limitations apply when protecting to AWS:

■ For Linux, AWS supports virtual machines with up to 40 volumes, including the boot volume.

■ For Windows, AWS supports virtual machines with up to 26 volumes, including the boot volume.

■ Note that C5/M5 instances have 28 available devices and each volume/NIC utilizes one device. Windows supports up to 26 volumes. For more information, see Elastic Network Interfaces.

■ GBT formatted disks are supported for data volumes only.

■ The following table describes the limitations per Import Method:

Import Method
OS	AWS Import		zImport for Data Volumes		zImport for all volumes
OS	Boot Volume	Additional Volume	Boot Volume	Additional Volume	Boot Volumes	Additional Volumes
Linux	1 TB	1 TB	1 TB	16 TB	2047 GiB*	16 TB
Windows	1 TB	1 TB	1 TB	16 TB	2047 GiB*	16 TB
* Some VMs use the MBR partitioning scheme, which only supports up to 2047 GiB boot volumes. If your instance does not boot with a boot volume that is 2 TB or larger,, the VM you are using may be limited to a 2047 GiB boot volume. See the relevant AWS documentation for more information: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html

■ For the AWS Import and zImport for Data Volumes import methods, the AWS ImportInstance API only supports single volume VMs. The boot volume of the protected virtual machine should not be attached to any other volume to successfully boot. For more information, see http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ImportInstance.html

It is strongly recommended to perform a Failover Test to ensure that the recovered instance is successfully running on AWS.

Adding Virtual Machines to a VPG - When the Recovery Site is Azure

■ 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. 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. GPv2 storage accounts are not supported.

■ Each ZCA requires a separate storage account. Multiple ZCAs using the same account is not supported.

■ For Linux distribution, refer to Azure documentation:

■ Linux on Azure-endorsed distributions: https://azure.microsoft.com/en-us/documentation/articles/virtual-machines-linux-endorsed-distributions/

■ Information for non-endorsed distributions: https://azure.microsoft.com/en-us/documentation/articles/virtual-machines-linux-create-upload-vhd-generic/

■ Ultra SSD storage is not supported.

Requirements for Replication From Azure

■ For Virtual Machines to be protected from Azure, the VM volumes must reside in the GPv1 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

Zerto uses the cloud native Azure Scale Set service to reduce RTO when failing over to Azure. When ZCA is installed in Azure, and the ZVM is up and running, an Azure scale set with one virtual machine is created in your Azure environment. The new virtual machine, created by the Scale Set, is prefixed with the site ID. When failing over to Azure, multiple VMs in the Scale Set are deployed for the recovery process and created in the ZCA VNet. When recovery is completed, these VMs are terminated.

The following requirements apply when protecting 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 protected virtual machines needs to have at least one NIC.

■ Internet access is required for the VMs created with the Azure scale set service.

■ ZCA primary NIC subnet requires minimum 50 IP addresses for the Azure Scale Set VMs.

■ Increase CPU quota, per Ds1v2 SKU family, to at least 50 for the Azure Scale Set service.

■ When failing over, up to 40 VMs are created of type Ds1_v2; with Ubuntu server 18.04 lts.

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 4TB

■ Reserve at least 2 CPUs and 4GB RAM for the machine using a subnet accessible by other Zerto 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:

■ 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	4TB	4TB
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 and Recommendations

Virtual Machines Limitations	# of Cores per subscription:	Default: 20 (max: 10K) Increase this default to at least 50.
	# of VMs per region per subscription:	Default is 20 Increase this default to at least 50.
	# of VMs per series, cores per subscription, per region:	Increase default to at least 50 for Ds1_v2.
	Resource groups per subscription:	800
Networking	Network interfaces per region:	350
	NICs per instance:	Depends on instance size: ■ Windows: https://docs.microsoft.com/en-us/azure/virtual-machines/virtual-machines-windows-sizes ■ Linux: https://docs.microsoft.com/en-us/azure/virtual-machines/virtual-machines-linux-sizes?toc=%2fazure%2fvirtual-machines%2flinux%2ftoc.json
	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:	500TB (# of entities (blobs, containers etc) within a storage account: unlimited)
	Max size of a page blob (vhd):	4TB
	Min size of a page blob (vhd):	20MB
	Max number of data disks:	Depends on instance size ■ Windows: https://docs.microsoft.com/en-us/azure/virtual-machines/virtual-machines-windows-sizes ■ Linux: https://docs.microsoft.com/en-us/azure/virtual-machines/virtual-machines-linux-sizes?toc=%2fazure%2fvirtual-machines%2flinux%2ftoc.json

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