It’s time for another book review and this time, I am reviewing “Disaster Recovery using VMware vSphere Replication and vCenter Site Recovery Manager”
This book is written by Abhilash GB (@AbhilashGB) who is amongst many things, a vExpert as well. The book is just over 140 pages long with five chapters. One thing I immediately liked about this book is that it’s based on VMware vSphere Replication 5.5 and VMware Site Recovery Manager (SRM) 5.5 – i.e. not an older 5.x version.
I am a fan of Packt Publishing books as they are short and sweet and focus on a particular task – just like a cookbook. Sometimes, that’s all you need to focus on something and get it out-of-the-way. I won’t go into the table of contents as that’s widely available. Rather, have a few words about the individual chapters, just to give you an idea of what’s in there.
This chapter is all about installation and configuration of vCenter Site Recovery Manager i.e. SRM. Of course, everything starts from here and in the beginning, important terms like RPO and RTOs are explained and the difference between them, along with their examples. There is also some discussion about the architecture and different components.
Following on from that, the author walks-through the installation process to be carried out at both the protected and recovery sites and points to consider before doing so. This chapter contains everything you’d have to do to have both sites fully configured. The assumption, however, is that storage at both sites supports the use of SRAs (Storage Replication Adapters). The examples used in the book follow HP StoreVirtual Appliances (very handy for home lab setups!) but any storage with such capabilities will be suitable. Home lab users: Not to worry as there is another way detailed in the latter chapters.
Once you have the environment, the next step is how to set up “Protection Groups” and “Recovery Plans” as that’s what you need to have machine protected and failed over in case of a disaster. Like the first chapter, there is a good amount of discussion (with illustrations) covering the architecture and also the decision points considered while designing such an environment. The author then goes into detailing the process of creating these objects, ready to be used in the next chapter.
All the activity so far was in preparation of what happens in this chapter, as this one goes into the actual process of failing over and then also failing back, after everything returns to normal i.e. after a “Planned Migration” or a DR scenario. Firstly, it explains the workflow that is followed when performing a “Test Failover” (a non-intrusive way of testing in SRM). There is also some explanation about why it works in the way it does – alleviating fears of IP conflicts. Then the book goes into discussing “Planned Migration” and “Disaster Recovery” scenarios and the process of carrying them out.
Once you’ve failed a site over, typically you would like to failback as well. That’s exactly the next topic and the steps involved in “Reprotecting” and failing back are discussed in detail here. The main distinguishing feature of SRM is automated recovery and the next section talks in detail about the many things to consider when planning for disaster recovery automation e.g. how you would like to recover machines, IP changes, power up sequences etc.
Up until now, the conversation assumed that a third-party vendor with SRA support is available at both sites, for use with SRM. Also, not every set up can afford or need to use SRM so the conversation now goes into using vSphere Replication 5.5 instead for protection of smaller environments.
Following the same theme as before, this chapter goes through the process of explaining the architecture of a vSphere Replication based setup and the deployment of it. As the process and granularity of this method is significantly difference, the chapter goes into quite a bit of depth in order to explain it properly.
The fifth and final chapter is dedicated to the configuration and use of the vSphere Replication 5.5 environment that has been set up. Once deployed, this chapter documents all the steps necessary to have a successful replication environment using vSphere Replication. The author goes into a good level of detail about how to set up replication between the two sites, the components involved and how to verify if everything is working as expected. There is also discussion around initial “seeding” of the datastores, which is extremely useful in low-bandwidth connectivity scenarios. All aspects of replication operations e.g. monitoring, reconfiguration etc. are also described in detail. Of course, the chapter then goes into the main topic i.e. failover and failback, while considering the important steps to take during and after those events.
I especially like this chapter as it also covers how to use SRM to automate these scenarios while using vSphere Replication as the replication engine. This is very useful as I have seen quite a few smaller environments who are good enough to afford SRM and like its automation features but don’t have the strength to invest in high-end storage systems. Plus, it also helps users who want to test SRM in their home labs. It also goes through the same concepts of Protection Groups and Recovery Plans but with a view of using a vSphere Replication setup.
Like most Packt Publishing books, this one also focuses on a particular topic i.e. Recovery using SRM and vSphere Replication and goes through the process of installing, configuring and using it. The book not only discusses the points to consider while designing such an environment but also has a step-by-step process of implementing it in it’s basic form, aided with an ample amount of screenshots. That’s ideal for someone who wants to carry out the process once in a lab, to understand it fully.
While one might argue that most of this information is available in the form of installation guides and blog posts, that’s generally true of pretty much any technical book available in the market. The key is to have a book that one can follow from start to finish to achieve a goal, without trying to cover every conceivable configuration option available under the sun. This book does just that!