5.5

Table 4‑1. How Testing a Recovery Plan Differs from Running a Recovery Plan (Continued)
Area of Difference Test a Recovery Plan Run a Recovery Plan
Effect on replication SRM creates temporary snapshots of
replicated storage at the recovery
site. For array-based replication,
SRM rescans the arrays to discover
them.
During a planned migration, SRM
synchronizes replicated datastores, then
stops replication, then makes the target
devices at the recovery site writable.
During a disaster recovery, SRM attempts
the same steps , but if they do not succeed,
SRM ignores the errors.
Network If you explicitly assign test networks,
SRM connects recovered virtual
machines to a test network. If virtual
machine network assignment is
Auto, SRM assigns virtual machines
to temporary networks that are not
connected to any physical network.
SRM connects recovered virtual machines
to a datacenter network.
Interruption of recovery plan You can cancel a test at any time. You can cancel the recovery in some cases.
How SRM Interacts with DPM and DRS During Recovery
Distributed Power Management (DPM) and Distributed Resource Scheduler (DRS) are not mandatory, but
SRM supports both services and enabling them provides certain benefits when you use SRM.
DPM is a VMware feature that manages power consumption by ESX hosts. DRS is a VMware facility that
manages the assignment of virtual machines to ESX hosts.
SRM temporarily disables DPM for the cluster and ensures that all hosts in it are powered on before
recovery begins. After the recovery or test is complete, SRM reenables DPM for the cluster. The hosts in it
are left in the running state so that DPM can power them down as needed. SRM registers virtual machines
across the available ESX hosts in a round-robin order, to distribute the potential load as evenly as possible.
SRM always uses DRS placement to balance the load intelligently across hosts before it powers on recovered
virtual machines on the recovery site, even if DRS is disabled on the cluster. If DRS is enabled and in fully
automatic mode, DRS might move other virtual machines to further balance the load across the cluster while
SRM is powering on the recovered virtual machines. DRS continues to balance all virtual machines across
the cluster after SRM has powered on the recovered virtual machines.
How SRM Interacts with Storage DRS or Storage vMotion
You can use SRM when protecting virtual machines on sites that are configured for Storage DRS or Storage
vMotion if you follow certain guidelines.
The behavior of Storage DRS or Storage vMotion depends on whether you use SRM with array-based
replication or with vSphere Replication.
Using SRM with Array-Based Replication on Sites with Storage DRS or Storage
vMotion
You must follow the guidelines if you use array-based replication to protect virtual machines on sites that
use Storage DRS or Storage vMotion.
n
If your storage array supports consistency groups, SRM is compatible with vSphere Storage DRS and
vSphere Storage vMotion. You can use Storage DRS and Storage vMotion to move virtual machine files
within a consistency group that SRM protects. If your storage array does not support consistency
groups, you cannot use Storage DRS and Storage vMotion in combination with SRM.
Chapter 4 Creating, Testing, and Running Recovery Plans
VMware, Inc. 39