Compared to the weeks before this week I had an easy week. A design review and some pre-sales related work, it is something else for a change. Something else that's new and exciting; I started working with John Arrasjid and Steve Kaplan on revising a book. It's not going to be a deep technical book, but it will focus more an introduction to virtualization. More on this later. It's top 5 time again, here we go:
- Scott Sauer – Get Thin Provisioning working for you in vSphere
So now that we have some of the basics out of the way, I wanted to
share my thoughts on thin provisioning. Like many organizations, we
get requests from our customers that err on the side of caution. They
want to plan for the worse case and ensure that their project and/or
application isn’t setup for failure. I don’t blame them really, I do
it myself all the time when I make coffee at home. I always end up
making more coffee than I typically drink, just in case I might need
that extra charge. The best way to do that is pad it, request more
than what you might really need, just in case something comes up down
the road. Virtual machine disk storage in some cases fits this same
profile. If my coffee maker granted me access to hot coffee on demand,
I would stop making extra coffee. Thin disks can give your end users
that capacity on demand so you can gain control of the padding effect
that typically takes place in most corporate organizations. - Rich Brambley – Thoughts and Images of vCloud Express
When vCloud Express was announced along with the vCloud API at VMworld 2009 in September I decided to sign up and try building VMware virtual machines (VMs) in the Cloud for myself. Being able to provision infrastructure as a service (Iaas) virtually with only a credit card has a certain useful appeal to me, and I wanted to see firsthand exactly what can be done and how much it costs.
This post summarizes my experience and touches on Terremark’s various options for building VMware Cloud VMs. I also quickly describe/illustrate the difference in charges for Linux versus Windows Cloud servers. This post contains a lot of screen shots, and at the end I’ll offer some opinions on the usefulness of vCloud Express and where this service might make sense for IT shops. - Chad Sakac – Cloud Storage – what the hell is EMC building?
The implications on storage infrastructure of these internal/external cloud models profound. Think of it this way… The vast majority of storage users in enterprises today have a provisioning model where the first step is “tell us whether you want 250GB or 500GB, whether it’s SAN or NAS, and the protection level – then wait a couple weeks as we process the request”. Of course, to fulfill the request, they purchased a wad of storage a year ago. How much did they buy? More than they needed – because god forbid they err with not enough (and in doing that ensure that they err completely in the opposite direction!). And, of course, it’s generally pretty “thickly” provisioned – and even if it is thin, it’s doled out and managed app by app, so the “pools” tend not to be too wide. - Vaughn Stewart – VCE-101: Oracle On VMware Without Limits
After a brief hiatus I am very eager to return to the ‘Virtualization Changes Everything’ series, and today’s post is an impromptu addition to our syllabus. Recently fellow VMware vExpert Steve Kaplan of INX published a rather thought provoking post rallying for the acceleration of the transformation to a 100% virtualized datacenter. Steve waxes poetic advocating acquisition decisions spanning compute, storage and network should be driven by their contribution to data center virtualization success and I would encourage everyone to read it. - Duncan Epping – DRS Deepdive Part 1 and Part 2
Keep in mind that when you change the “Migration Threshold” the value of the “Target host load standard deviation” will also change. In other words the Migration Threshold dictates how much the cluster can be “imbalanced”. There also appears to be a direct relationship between the amount of hosts in a cluster and the “Target host load standard deviation”. However, I haven’t found any reference to support this observation. (Two host cluster with threshold set to three has a THLSD of 0.2, a three host cluster has a THLSD of 0.163.) As said every 5 minutes DRS will calculate the sum of the resource entitlements of all virtual machines on a single host and divides that number by the capacity of the host:
sum(expected VM loads) / (capacity of host)
