The replication method is an approach to extract data from the source system and create a copy for data recovery purposes. There are different replication methods available to store a copy of data as per the storage type for business process continuation. Replications can be implemented using the following methods:

• Array-based replication: In this, built-in software automatically replicates data. However, both the source and destination storage arrays should be compatible and homogenous to replicate data. A storage array contains multiple storage disks in a rack.

Large enterprises use array-based replication due to the ease of deployment and the reduction in the compute power host system. You can choose array-based replication products such as HP Storage, EMC SAN Copy, and NetApp SnapMirror.

• Network-based replication: This can copy data between a different kind of heterogeneous storage array. It uses an additional switch or appliance between incompatible storage arrays to replicate data.

In network-based replication, the cost of replication could be higher as multiple players come into the picture. You can choose from networked-based replication products such as NetApp Replication X and EMC RecoverPoint.

• Host-based replication: In this, you install a software agent on your host that can replicate data to any storage system such as NAS, SAN, or DAS. You can use a host-based software vendor, for example, Symantec, Commvault, CA, or Vision Solution.

It's highly popular in Small and Medium-Sized Businesses (SMBs) due to fewer upfront costs and heterogeneous device compatibility. However, it consumes more compute power as the agent needs to install on host operating system.

• Hypervisor-based replication: This is VM-aware, which means it can copy the entire virtual machine from one host to another. As organizations mostly use a virtual machine, it provides a very efficient disaster recovery approach to reduce the RTO.

Hypervisor-based replication is highly scalable and consumes fewer resources than host-based replication. It can be carried out by native systems built into VMware and Microsoft Windows. You can choose a product such as Zerto to perform hypervisor-based replication or another product from one of the various vendors.

Previously, in Chapter 3, Attributes of the Solution Architecture, you learned about scalability and fault tolerance. In Chapter 6, Solution Architecture Design Patterns, you learned about various design patterns to make your architecture highly available. Now, you will discover multiple ways to recover your system from failure and make it highly reliable.