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: