Import Methods for AWS

During recovery operations, Zerto uses a combination of the following APIs and methods to convert the Amazon S3 objects into recovery disks in EC2 as EBS disks:

■ Import-instance: for the boot volume

■ Import-volume: for data volumes

■ Zerto Import - zImport, an import method that does not have the same limitations as the AWS APIs. It creates an AWS EC2 instance per protected VM volume, called zImporter, to convert the S3 objects and write them to a zImport local disk. When all the data has been imported and its disk have been attached to the recovered instance, the zImport instance is terminated.

■ zImporter is based on an official AWS Linux AMI (Amazon Machine Image), into which a script is injected to perform the import. The script is located online and downloaded to the zImporter, and thus the zImporter requires internet access in order to access and download the script. The zImport instance is therefore created with a public IP.

■ The only network in the customer environment that is certain to have internet access is the network that the ZCA is connected to.

■ To ensure that the zImport instance cannot be accessed from the outside world, a security group is created. During a recovery operation the zImport instance is connected to this security group. All inbound traffic is blocked and only outbound traffic to access the script online is allowed. The security group is deleted at the end of the recovery operation.

■ The default zImporter instance type is c4.8xlarge and the AWS EC2 default maximum instance quota is 20. If during the creation of zImport instances the maximum EC2 instance quota is reached, the creation of the next and subsequent zImport instances will be queued, increasing the RTO. If during recovery operations, the ZVM identifies a VPG with the potential to exceed the EC2 instance quota, the user will receive an alert with advice to contact AWS support to increase the service limits in order to improve RTO.

■ GPT formatted disks are supported for data volumes only, when using either of the zImport methods.

■ When using either of the zImport methods, each volume is created with EBS disk of type io1 with maximum 1000 EBS Provision IOPS allocated. EBS disk type can be changed post recovery without downtime, see the relevant for more information see the relevant AWS documentation. The minimum disk size for io1 is 4GB.

■ The default Max EBS Provision IOPS quota in a region across all io1 disks is 40000 EBS Provision IOPS, meaning that with 1000 EBS Provision IOPS per volume, the maximum possible number of volumes is 40. If the Max EBS Provision IOPS quota is reached, the failover process will switch to using slower gp2 disks. An event will notify the user of this, and recommend that the user contact AWS support to increase the Max EBS Provision IOPS quota.

■ Depending on the desired RTO during recovery operations, or when testing failover, the user can select an import method per VPG or per virtual machine from the following options:

■ Zerto Import for Data Volumes

■ Zerto Import for All Volumes

This method is the default setting and has a faster RTO than AWS Import. This method uses a combination of the AWS import-instance API for the boot volume, and the zImport method for data volumes.

■ Each machine that you intend to protect must have at least 250MB free space. This is because AWS adds files to the recovered machines during failover, move, test failover, and clone operations.

■ Protected boot volumes are recovered in EC2 as EBS disks with magnetic disk type. Virtual machines with disks that are less than 1GB are recovered with disks of 1GB. Temporary disks may be created based on the selected instance size.

■ 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

This method creates an AWS EC2 instance per protected VM volume, called zImporter, to convert the S3 objects and write them to a zImport local disk. When all the data has been imported and its disk have been attached to the recovered instance, the zImport instance is terminated.

■ This import method cannot be used for the recovery of protected virtual machines running Windows Server 2008R2. To support this operating system please contact Zerto support.

Note: 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 2TB or larger, the VM you are using may be limited to a 2047 GiB boot volume size. Non-boot volumes do not have this limitation. See AWS Documentation for more information: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSVolumeTypes.html

When using this import method, if the protected virtual machine using this import method is running Windows 2012, Windows 2012R2 or Windows 2016, the following drivers must be installed on the protected virtual machine before starting recovery operations:

The following steps must be performed to ensure that the virtual machine will be able to run on the recovery site:

g) Follow the instructions at the site for downloading and installing all the Windows PV Drivers 8.2.0 drivers.

Note: If these drivers are installed on a VM running Windows 2012R2, the other AWS import methods will fail. To overcome this, you must uninstall the drivers before using the other AWS import methods.

IMPORTANT :

When using this import method for Windows machines, ZertoTools for AWS needs to be run on the protected Windows virtual machine in VMware before VPG creation. For more information, see ZertoTools for AWS.

This method uses a combination of the AWS import-instance and import-volume APIs for the boot and data volumes respectively. This was the only method supported until version 5.5.

■ Each machine that you intend to protect must have at least 250MB free space. This is because AWS adds files to the recovered machines during failover, move, test failover, and clone operations.

■ Protected boot volumes are recovered in EC2 as EBS disks with magnetic disk type. Virtual machines with disks that are less than 1GB are recovered with disks of 1GB. Additional volumes might be created in the recovered instance, dependent on the instance type used for the recovery. These volumes can be ignored.

■ Protected volumes are recovered in EC2 as EBS disks with magnetic disk type. Virtual machines with disks that are less than 1GB are recovered with disks of 1GB. Additional volumes might be created in the recovered instance, dependent on the instance type used for the recovery. These volumes can be ignored. Temporary disks may be created based on the selected instance size.

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

■ C3	■ I2
■ C4	■ R3
■ D2	■ M4 (excluding M4.16xlarge)