Yellow Bricks

by Duncan Epping

VMware

Impact of decisions…

· ·

I’ve been conducting VCDX Defense Interviews for a while now. Last week in Las Vegas during PEX something struck me and I guess this post by Frank Denneman is a good example…

On a regular basis I come across NFS based environments where the decision is made to store the virtual machine swap files on local VMFS datastores. Using host-local swap can affect DRS load balancing and HA failover in certain situations. So when designing an environment using host-local swap, some areas must be focused on to guarantee HA and DRS functionality.

Every decision you make has an impact on your design/environment. What does a decision exactly impact? In most cases every decision impacts  the following:

  1. Cost
  2. Availability
  3. Performance

In the example Frank wrote about (see quote) a decision which clearly had an impact on all three. Although at the time it might have been a best practice the decision to go along with this best practice still had an impact on the environment. Because it was a best practice this impact might not have been as obvious. But when listed as follows I hope you understand why I am writing this article:

  • Costs – Reduced costs by moving the .vswp file to local disks.
  • Performance – VMotion performance is effected because .vswp files need to be copied from HOST-A to HOST-B.
  • Availability – Possibly less availability when the amount of free disk space on local VMFS isn’t sufficient to restart VMs in case of disaster.

As you can see a simple decision has a major impact, even though it might be a best practice you will need to think about the possible impact it has and if this best practice fits your environment and meets your (customer) requirements. Another great example would for instance be LUN sizing. So what if I would randomly pick a LUN size. Lets say 1TB:

  • Cost – As the average VM size is 35 GB, I want a max of 20VMs on a datastore and I need 20% of overhead for vswp files and snapshots I end up with max usage of 840GB. Added overhead: 160GB!
  • Availability – Although the availability of the datastore will be unaffected the uptime of your environment might change. When a single datastore fails you will lose 1TB worth of data. Not only will you lose more VMs, restoring will also take longer.
  • Performance – Normally I would restrict the LUN size to reduce the amount of VMs on a single datastore. More VMs on a datastore means more higher possibility of SCSI reservation conflicts.

The VCDX certification is not about knowing all the technical details, of course it is an essential part of it, it’s about understanding the impact of a decision. It’s about justifying your decision based on the impact it has on the environment/design. Know the pros / cons. Even if it is a best practice it might not necessarily apply to your situation.

VMware Partner Exchange 2010

· ·

I attended VMware Partner Exchange this week in Las Vegas. I must say I was impressed. To be completely blunt; I wasn’t impressed with Vegas. Vegas is definitely not my cup of tea. I love a bit of “history” and Vegas hardly has any. Give me San Francisco, New York, Boston or any other city anytime!

I do however was impressed with Partner Exchange. From a logistics standpoint PEX was well organized so my compliments to the organization. The labs, the sessions, the workshops… I wish I could have joined any of these. I’m not complaining though as being part of the VCDX Panel is also a great experience. Seeing the creative solutions people come up with is a learning experience for me as well. Some people have a different view on a concept or solution and this also gives me food for thought. Another thing what I love about being part of the panel is making people think about their own design. I can’t say much about the interviews I conducted though as the NDA police would kill me. I hope to see some of you who are taking the defense in Munich!

I did manage to see the keynote by Steve Herrod by the way. I was impressed with all the insights Steve gave in terms of upcoming products, brand new projects and even a couple tech previews. I am looking forward to the upcoming version of VMware View and a new project which I can’t disclose as the VMware NDA Police would again kill me. I am also looking forward to start using Zimbra.

Especially “Zimlets” seem to be really powerful. Zimlets are basically hook-ins for your email/colaboration tool. A good example would be an Oracle plugin. When an email for instance contains a PO number the PO number will appear as a link to the PO system. But not only a link, when hovering over the link a pop-up will appear with for instance the total amount for the PO and the approval status.

Other upcoming new features that were revealed are IO DRS, Memory Compression and a new View management interface. I recommend reading some of the other blog posts on this topic as there is a lot I can’t write about:

And by the way; Congrats Frank and Andrew Mitchell for becoming VCDX 029 and 030!

vSphere Security Hardening Guide script by @lamw

· ·

A couple of weeks ago I blogged about the vSphere Security Hardening Guide. Just a couple of days later William “the king of Perl” Lam already produced a script that checks the Hardening Guide best practices against your environment. It produces a great html based report.

Source

While going through the COS/HOST and VM documentation, I noticed there were quite a few checks that might benefit from having a script to validate the guidelines and that was the motivation for this script. Not all sections can be validated using the vSphere APIs and will require some manual validation and I’ve seperated the types of passes whether it’s a fail, pass or manual (which requires user intervention).

The script allows you to run the current existing guides as of (01/29/2010) against vCenter 4.0 hosting ESX(i) 4.0 hosts/virtual machines OR run it against an individual ESX(i) 4.0 host. The script allows you to run a subset of the checks and against different type of validation (ENTERPRISE,DMZ or SSLF). Upon completion, a report is generated including a grade for your environment.

A couple of details on the features:

  • Email report
  • Ability to execute subset of the checks (COS,HOST,VCENTER,VNETWORK,VM)
  • Ability execute specific test suite (ENTERPRISE,DMZ,SSLF)
  • Detail HTML summary report with letter grade

You can find an example report here. Great work again William, keep it up!

Top-25 virtualization bloggers

· ·

Eric Siebert just published the results of the Top-25 bloggers poll. Over 700 people voted and several bloggers entered the top-25 like Frank Denneman and Alan Renouf. I would like to thank everyone for voting on me. It’s a true honor to be part of a list like the following, let alone being voted as the number one virtualization blogger…

  1. Yellow Bricks – Duncan Epping – 158 #1 votes – total score of 4,191
  2. Virtual Geek – Chad Sakac – 111 #1 votes – total score of 2,938
  3. Scott Lowe’s Blog – Scott Lowe – 56 #1 votes – total score of 2,889
  4. NTPro.nl – Eric Sloof – 22 #1 votes – total score of 2062
  5. RTFM Education – Mike Laverick – 7 #1 votes – total score of 1,734
  6. Virtualization Evangelist – Jason Boche – 13 #1 votes – total score of 1,482
  7. VM/ETC – Rich Brambley – 5 #1 votes – total score of 1,138
  8. Gabe’s Virtual World – Gabrie van Zanten – 8 #1 votes – total score of 1,096
  9. Virtual Storage Guy – Vaughn Stewart – 58 #1 votes – total score of 990
  10. Virtu-Al – Alan Renouf – 18 #1 votes – total score of 831

I borrowed the list from Arnim who blogged about it yesterday, for the full list with all 66 Bloggers check Eric’s new article.

Vote Now!

· ·

Eric Siebert has created a new poll to update his top 20 bloggers list. As many of you know I had the honor to be on the number one spot for the last three updates. Hopefully I will be part of the top 3 again, but the competition is huge. People like Chad Sakac, Scott Lowe, Scott Drummonds, Alan Renouf and Jason Boche(just to name a few) have a great reputation and have published amazing articles over the last 6 months or longer.  Looking back at the past 6 months(since the last voting) my top articles in terms of unique views were:

Let the games begin, Start the voting now!