Today's business obligations require administrators to have a solid disaster recovery plan in place to keep virtual machines running with minimal downtime. There are a number of ways and products to protect your virtual environment, including VMware's vCenter Site Recovery Manager (SRM).
In the book Disaster Recovery Using VMware vSphere Replication and vCenter Site Recovery Manager, author Abhilash GB explains the inner workings of VMware SRM and vSphere Replication and how to perform a variety of procedures, including array-based replication, planned migration, failover and failback.
In Chapter 1, which is available to read via PDF, the author details the basics of SRM -- software designed to automate disaster recovery testing and failover -- and describes its architecture and the requirements for it to perform properly.
With SRM, he explains the need for array managers and a Storage Replication Adapter (SRA). Array managers are necessary for SRM to communicate with the storage array. The array manager uses the SRA to gather the replicated information from the array. The author offers step-by-step directions with illustrations to take you through the installation of SRM, the SRM plug-in and SRA.
Chapter 1 highlights:
Installing SRM on the protected and recovery sites
VCenter SRM has to be installed at both the protected and recovery sites for the disaster recovery setup to work. The installation process is identical regardless of the site it is being installed on; the only difference is that at each site, you will be registering the SRM installation to the vCenter Server managing that site.
SRM can either be installed on the same machine that has vCenter Server installed or on a different machine. The decision to choose either one of the installation models depends on how you want to size or separate the service-providing machines in your infrastructure. The most common deployment model is to have both vCenter and SRM on the same machine. The rationale behind this is that SRM will not work in a standalone mode; this means that if your vCenter Server goes down, there is no way you could access SRM. Like vCenter Server, SRM can be installed on a physical or virtual machine.
Another factor that you must take into account is the installation of SRA. SRAs have to be installed on the same machine where you already have SRM installed. Some SRAs need a reboot after installation. So, it is important to read through the storage vendor's documentation prior to proceeding to make a deployment choice for SRM. If the vCenter downtime is not feasible, then you will have to consider installing SRM on a separate machine.