Information Storage and Management: Storing, Managing, and Protecting Digital Information in Classic, Virtualized, and Cloud Environments, Second Edition

Chapter 11

Local Replication

Key Concepts

Data Consistency

Host-Based Local Replication

Storage Array-Based Local Replication

Copy on First Access (CoFA)

Copy on First Write (CoFW)

Network-Based Local Replication

Restore and Restart Considerations

VM Replication

In today's business environment, it is imperative for an organization to protect mission-critical data and minimize the risk of business disruption. If a local outage or disaster occurs, fast data restore and restart is essential to ensure business continuity (BC). Replication is one of the ways to ensure BC. It is the process to create an exact copy (replica) of data. These replica copies are used for restore and restart operations if data loss occurs. These replicas can also be assigned to other hosts to perform various business operations, such as backup, reporting, and testing.

Replication can be classified into two major categories: local and remote. Local replication refers to replicating data within the same array or the same data center. Remote replication refers to replicating data at a remote site. This chapter provides details about various local replication technologies, along with restore and restart considerations. This chapter also details local replication in a virtualized environment. Remote replication is covered in Chapter 12.1.

11.1 Replication Terminology

The common terms used to represent various entities and operations in a replication environment are listed here:

• Source: A host accessing the production ...