American Megatrends ManageTrends 2.7, User Manual

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StorTrends® 1300 User’s Guide (StorTrends iTX version 2.7) 242
StorTrends Asynchronous Replication
StorTrends comes with an extensive support for Asynchronous or Periodic Replication.
This feature is offered in two different flavors:
•
Snap Assisted Replication (SAR)
•
Journal Assisted Replication (JAR)
Snap Assisted Replication
StorTrends servers offer a very innovative and feature-rich periodic replication suite
called Snap-Assisted-Replication (SAR). This form of replication is used where Service
Level Agreement (SLA) permits the administrator to have a relaxation in Recovery Point
Objective (RPO) and Business economics does not permit synchronous replication.
Based on Redirect-On-Write (ROW), this stack provides Near-CDP snapshots. Here,
storage capacity is provisioned via a very space-efficient three-level capacity allocation
map, which allows hundreds of snapshots to be created in the most capacity-efficient
fashion. Inherent thin-provisioned allocation of snapshot space does not necessitate any
capacity planning and manual reservation of space for snapshots. This innovation in
snapshot technology allows StorTrends to render industries most efficient (and easily
manageable) Asynchronous Replication, with minimal RPO. After the initial snapshot
replication, subsequent snapshot replications uses delta-snapshot mount to guarantee
minimal transfer updates to the recovery site, mirroring only differences between
subsequent snapshots instead of the entire snapshot.