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Top 5 Planet V12n blog posts week 41

It was VCDX Defense week this week in Frimley and there were several panels scheduled. I met some cool people and learned a lot during this week. Next week there are VCDX Defense panels in Munich! If you are working towards VCDX, don't forget that panels normally are only scheduled around VMware Events. This means that there are only a couple times per year you can get certified. Blog wise there were a lot of great posts again this week. It was hard to pick only 5, but I did manage to do so:

  • Frank Denneman – Lefthand SAN – Lessons learned
    Blocks will be stored on storage nodes according to replication level.
    If a LUN is created with the default replication level of 2-way, two authoritative blocks are written at the same time to two different nodes.
    If a 3-way replication level is configured, blocks are stored on 3
    nodes. 4-way = 4 nodes. (Replication cannot exceed the number of nodes
    in the cluster)
    SAN IQ will always start to write the next block to the second node containing the previous block.
  • Duncan Epping -  Slot sizes & Alan Renouf – HA Slot size information
    Five hosts, each host has 16GB of memory except for one host(esx5)
    which has recently been added and has 32GB of memory. One of the VMs in
    this cluster has 4CPUs and  4GB of memory, because there are no
    reservations set the memory overhead of 325MB is being used to
    calculate the memory slot sizes. (It’s more restrictive than the CPU
    slot size.) This results in 50 slots for esx01, esx02, esx03 and esx04. However,
    esx05 will have 100 slots available. Although this sounds great
    admission control rules the host out with the most slots as it takes
    the worst case scenario into account. In other words; end result: 200 slot cluster
  • Eric Siebert – New Twitter lists for the top bloggers and VMware/Virtualization people
    Twitter is a great tool for communicating with other virtualization
    professionals, but trying to find interesting people to follow
    especially if you are new to Twitter can be time-consuming and
    difficult. For that reason I put together some Twitter group lists to
    make following people that are related to VMware virtualization easier.
    The first list is just from my Top 20 blogger list on my vLaunchpad that was decided by a poll I did months ago, consequently that one was really easy to put together.

    The second list is the top 100 people to follow that are related to
    VMware & virtualization, this one wasn’t easy at all to put
    together. The list started at about 300+ people that was part based on
    my followers and followings of other popular virtualization bloggers.
    Once I discovered that TweepML had a limit of 100 people I had to
    really trim that list down a lot, that wasn’t an easy task, especially
    the last 20 or so. There were some people I really wanted to keep on
    there but was forced to remove, the 100 person limit made for some
    difficult decisions.
  • Hany Michael – vSphere 4.0 vNetwork Distributed Switch (vDS) – Video Demonstration + Architecture Diagram
    The diagram reflects the exact configuration on the video. I’ve
    done this intentionally to make it easier and faster for any one new to
    the vDS to understand the concept and the various configuration aspects. As I mentioned above, due to the very short period of time that I
    had, I will most probably modify small parts in the diagram to achieve
    better results. You can come back and check the version number of the
    diagram to download the latest updates.
  • Scott Drummonds – Top Five VROOM! Entries for 2009
    I love VMware’s performance blog, VROOM!  It is our most popular
    performance communication vehicle and its content is backed by a
    stellar engineering team with unmatched integrity.  Each article
    details the nuances of VMware performance and educates on application
    and platform best practices.  I love all the articles but am always
    surprised as to which our readers find most popular.  Here is a
    countdown of the five entries most read in 2009.
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Duncan Epping

About Duncan Epping

Duncan is a Chief Technologist working in the Storage and Availability Business Unit at VMware, serving as a partner and truster adviser to EMEA customers. He is the co-author of several books, including the vSphere Clustering Deepdive series and Essential Virtual SAN. He is the owner and main author of virtualization blog yellow-bricks.com.