With vSphere 5.0 a brand new primitive has been introduced which is called Dead Space Reclamation as part of the overall thin provisioning primitive. Dead Space Reclamation is also sometimes referred to as unmap and it enables you to reclaim blocks of thin-provisioned LUNs by telling the array that specific blocks are obsolete, and yes that command used is the [...]

I was asked about this a couple of times over the last few days so I figured it might be an interesting topic. This is described in our book as well in the Datastore Cluster chapter but I decided to rewrite it and add some of it into a table to make it easier to digest. Lets start of with [...]

Yes, here it is… the moment we’ve all been waiting for… vSphere 5.0. Finally announced today, and on top of that also new releases of vCD (1.5), SRM (5.0), vShield (5.0) and of course a new product called the vSphere Storage Appliance. Over the last months I have been working hard on collateral for this launch and soon it should [...]

** Update: Available now: paperback full |paperback black & white ** After months of hard work the moment is finally there, the release of our new book: vSphere 5.0 Clustering Technical Deepdive! When we started working, or better said, planning an update of the book we never realized the amount of work required. Be aware that this is not a [...]

The Product Management Team reached out to me this week and asked me if I could help getting some real world data around HA by posting some information about a survey. These surveys are generally used to priorities features or even add functionality. So if you want to contribute please take the survey. It will roughly take 4 minutes to [...]

There has been a lot of discussion in the past around Disk.SchedNumReqOutstanding and what the value should be and how it relates to the Queue Depth. Jason Boche wrote a whole article about when Disk.SchedNumReqOutstanding (DSNRO) is used and when not and I guess I would explain it as follows: When two or more virtual machines are issuing I/Os to [...]

For those who are not following Frank’s blog, he just posted a sneak peek of the upcoming vSphere Clustering book. It looks really really slick in full color. I promise you won’t be disappointed. Go to Frank’s article for more details.