One of my readers recently contacted me about how SRM communicates to vCenter both during an install, and then afterwards once the service is up and running. The odd thing is this… During the install the communication to vCenter appears to be non-secured on TCP port 80, but after the install is on the secured port of TCP 443… In the book I conjecture that some redirection takes place, its actually a little bit more sophisticated than that…

Here’s what the offical guide says: 

Port 80 is provided as the default to use for the initial connection to the remote site. After the initial HTTP connection is made, the two sites establish an SSL connection over port 80 to use for subsequent connections.

Duncan Epping on his Yellow Bricks site has this more revealing statement:

http://www.yellow-bricks.com/2009/08/11/srm-faq/

Why is Port 80 used in the install but port 443 later? During install of SRM port 80 is specified and you cannot type in 443, but after the install is complete than SRM talks to VC on 443, so why is 80 specified in the install? Even though SRM uses SSL when it communicates to VC, it does not use port 443. SRM establishes a TCP connection to port 80, than uses an HTTP CONNECT request to establish a tunnel to the VC servers, then does an SSL handshake with the VC over that tunneled connection. The SRM installation enforces these semantics.

Thanks to Bas Vinken for bring these two bits of information to my attention. Quite why the communcation is this done this way isn’t really explained. But I guess it is a reminder that port numbers are some what arbitary, and they follow a convention of being associated with certain services – I guess you would calll them the “well-known ports”. But at the end of the day, there’s nothing hard coded about these ports and how they are used..

Introduction:

As you might know SRM 5.0 introduces support for “vSphere Replication” (VR) – where virtual appliances are deployed to assist in the replication of VMs from the Protected Site to the Recovery Site. What you might not know – is whilst this works perfectly for recoveries where the VM moves from one site (say SiteA: New York) to another (say SiteB: New Jersey) – there is no automated method of failback. That is to say, moving the VM back from the Recovery Site (SiteB: New Jersey) to Protected Site (SiteA: New York).

SRM 5.0 does introduce a new “automated failback” feature – its a combination of running a “reprotect” process to invert the “normal” path of replication – and then running a Recovery Plan to move the VMs back. Sadly, that “reprotect” and failback process didn’t make it into the first release of VR. That means a more “manual” process has be undertaken to a.) prepare for the failback and b.) return SRM and VR back to a state that it was in before the failover took place. For an experienced SRM Administrator (sic) this isn’t too much of chore or difficult – but if you are new to SRM, and intend to use VR – then it could be a bit of challenge. That’s what this article is all about.

I’ve been prompted to write this because I know that my upcoming SRM book will have a very long chapter on failover/failback but it is very much from slanted from the position of array-based replication – and there’s very little if any detail on how this process pans out when your using SRM with VR. This article is intended to plug that gap for my readers who buy the book. It’s shame that this didn’t make it into the book, but that is publishing deadlines for you. As it is, this likely to change over the lifetime of SRM 5.0 – and this article will be  darn easier to maintain and update…

For sometime I’ve been using the scenario of fictitious company called “Corp.com” which has two sites New York and New Jersey in my books. New York is meant to be the production or Protected Site during normal business operations, and New Jersey is an ancillary location to Corp.com – and is used for many purposes – in this case as the Recovery Site in SRM.

(more…)

I’m pleased to announce the general availability of my new book. It’s free to download as a PDF file – and if you prefer a hard-copy you can print a physical copy of the book from LULU.COM.

Both the PDF and the hard-copy are available from the LULU.COM website.

Some stats:”

• The book is just short of 100,000 words
• 400 pages
• 6 months to complete from start to finish
• Additional 100 pages of text and supporting graphics from the SRM 1.0 book
• Additional 3 chapters

What’s New?

• All graphics updated to vSphere4
• All new theme of the New York and New Jersey – Protected and Recovery Site
• How setup replication for EMC Celerra, Clariion CX3, NetApp Filers and HP Lefthand VSA
• Integrated with these three storage vendors  – so I cover what happens in EMC, NetApp, and HP when recovery plans are tested or run
• Coverage of the new “Shared Site” configuration
• Integrating PowerCLI scripts to the Recovery Plan
• How to automate VMware SRM using the SRM SDK API
• Updated PowerCLI chapter specific to the new vSphere4 Distributed vSwitches

This time around I won’t be taking a royalty for the new book.  I would however, strongly urge you to donate money to my chosen charity. That charity is Unicef and this is what they do:

“UNICEF works with families, communities and governments in more than 190 countries worldwide to protect and promote the rights of all children. We are guided throughout our work by the UN Convention on the Rights of the Child, which guarantees every child the same rights: to an education, to a childhood, to be as healthy as possible, to be treated fairly and to be heard. UNICEF works in all these areas, and does so in a joined up way to achieve the best possible outcomes for children.”

So before you begin to read book, please pause to think of the millions of children you help by making a relatively small donation.

The recommended donation is $10 (US Dollars) or the equivalent in your currency.

http://www.supportunicef.org/forms/whichcountry2.html

Click the graphic to download/order the book, but before you do – please consider a donation of some kind.

I would like to take this opportunity to welcome Hyper9 as new advertiser to RTFM. To celebrate this here’s another here’s Chapter 4 from my SRM book…

Remember you can still buy the book in EMEA at much reduced cost via the VMworld EMEA store (whilst stocks last) – alternatively, if you prefer to buy the SRM book in the US it is still available on LULU.com. 

Work is coming along well with vSphere4 book. My hope is that by the end of the month – I should have working copy I can distribute to my VMTN reviewers and internally to VMware. The plan is to still have an “authors” edition out on LULU on the day of the GA – with a hope of having the final “cut” so to speak ready for VMworld in San Francisco. I’m in discussion with McGraw-Hill about potentially publishing the book via them – so that could change…

Download Chapter 4

To celebrate the arrival of yet another advertiser on RTFM – it’s my pleasure to release chapter 2 & 3 of my popular VMware Site Recovery Manager book. The chapter on Lefthand Networks VSA is somewhat dated – one of my projects is to update my chapter on iSCSI in my vSphere4 book to match the functionality of the new VSA… and also at the same time update the chapter on LHN so it matches with SAN IQ8.

Remember you can still buy the book in EMEA at much reduced cost via the VMworld EMEA store (whilst stocks last) – alternatively, if you prefer to buy the SRM book in the US it is still available on LULU.com. 

Work is coming along well with vSphere4 book. My hope is that by the end of the month – I should have working copy I can distribute to my VMTN reviewers and internally to VMware. The plan is to still have an “authors” edition out on LULU on the day of the GA – with a hope of having the final “cut” so to speak ready for VMworld in San Francisco.

Download Chapter 2

Download Chapter 3

To celebrate the arrival of my first advertiser to RTFM. I would like to begin the process of slowly releasing my SRM book free to download. The SRM book will remain commerically available for sometime – and when SRM 2.0 the “old” SRM1.0 book will become completely free. As I release each chapter I will be reviewing the content for any old typos, and rolling those changes through to the commerical book. Remember PDFs are great but when a book runs to 300+ pages it is actually cheaper to buy a copy than it is to take it to a printers (believe you me I learned this during the proofing phase how expensive) plus you get it delivered to your door with a perfect binding! My next free chapter will update the content I created about Lefthand Networks VSA, which is now on SAN/IQ Version 8. There aren’t a huge amount of differences so hopefully it won’t take long…

This book is still based on the original GA version – not the recent U2 edition. U2 did introduce new features and some options ceased being experimental. But not enough changes we introduced to force me to stop work on vSphere4. But I will as each chapter comes out – review the content and update it accordingly.

Enjoy your first free chapter!  

Chapter 1: Introduction to Site Recovery Manager