This was probably one of the toughest Top-5′s to write as I had the week off this week. I basically had to catch-up with a whole week of Planet V12n. One of the most annoying things about it is that half of the blogs on PlanetV12n enabled “content summary only”. Yes I know you will have a couple of extra visits, but isn’t blogging about getting people to read your content instead of being “numbers”(visits) focused? Now that I got that off my chest lets move on to what this article is about. It’s about the 5 top articles this week:

• Vaugn Stewart – VCE-101 Thin Provisioning Part 1 – The Basics & VCE-101 Thin Provisioning Part 2 – Going Beyond
  Like the thick format, thin VMDKs are not formatted at the time of
  deployment. This also means that data that needs to be written must
  pause while the blocks required to store the data are formatted. The
  formatting operation only occurs on demand at anytime an area of the
  virtual disk, which has never been written to, is required to store
  data.
• Chad Sakac – Solid State Disk will change the storage world…
  But surely, if you were looking for performance, you wouldn’t use the SATA disk, right? You would probably use a 15K RPM FC disk. Those cost about $1000. They do about 200 random write IOPs. So, you would need 20 of them to do what that $115 SSD could do. That’s 0.2 IOps per dollar – or 170x more expensive than the SSD on a IOps/$ basis. Oh, you think SAS 15K drives are a better deal? They are – than FC disks. A 15K SAS disk on Pricewatch costs about $210, and they also do about 200 IOps. that’s 0.95 IOps per dollar – or 37x more expense than the SSD on a IOps/$ basis.
• Luc Dekens – dvSwitch scripting – Part 4 – NIC teaming
  The double Service Consoles and vmKernel connection might look confusing at first. But when you select one these connections, the vSphere client will show you to which uplink a specific connection is going.

  To increase the availability of the dvSwitch, I will show how to add two pNics and how to activate and configure NIC Teaming.

  When I created the dvSwitch I configured it for two uplink ports (per host). Since I’m adding two pNics, I will first have to change the maximum number of dvUplink ports.

• Gabrie van Zanten – Design tips for VMware vSphere 4
  Recently at the Belgium VMUG I gave a presentation in which I covered some design tips for VMware vSphere 4. I talked about some business decisions that, how boring they may seem, are crucial for your design. I covered some security requirements you should check with the security department of the organisation and of course advised good capacity planning which also is very important for your design.

  What the average geek found most interesting where topics like: “What size of ESX host will you buy?”, “How to run vCenter in a VM”, “VMFS best practises”, “Understanding queue depth and lun size” and more….

• Simon Gallagher – iSCSI LUN is very slow/no longer visible from vSphere host
  Due to too many SCSI reservation conflicts, so hopefully it wasn’t looking like corruption but a locked-out disk – a quick Google turned up this KB article – which reminded me that SATA disks can only do so much

  Multiple reboots of hosts and the OpenFiler hadn’t cleared this situation – so I had to use vmkfstools to reset the locks and get my LUN back, these are the steps I took..

  You need to find the disk ID to pass to the vmkfstools –L targetreset command, to do this from the command line look under /vmfs/devices/disks

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)