VMware PEX 2010 was great… but it did mean I was extremely busy and didn't have time to create the top-5. I just picked the 5 best reads this week. Check it out:
- Jason Boche – My VCDX defense experience
The first 75 minutes is spent “defending” my design. I’ve got about a
15 slide deck to get through and to use as reference throughout the
design defense. I’d highly recommend putting as much reference as you
can in the slide deck which you can yourself refer to during the
defense. It will help illustrate design choices and jog your memory
for design elements which you’ve forgotten due to nervousness. The
first 5-10 minutes I was pretty nervous and stuttered once or twice
during my presentation. After that, I warmed up and it felt more like a
good technical discussion with co-workers which I enjoyed.
- Mike La Spina – Running ZFS over NFS as a VMware Store
In this architecture we are defining a fault tolerant configuration
using two physical 1Gbe switches with a quad or dual Ethernet
adapter(s). On the OpenSolaris storage head we are using IPMP aka IP
Multipathing to establish a single IP address to serve our NFS store
endpoint. A single IP is more appropriate for VMware environments as
they do not support multiple NFS IP targets per NFS mount point. IPMP
provisions layer 3 load balancing and interface fault tolerance. IPMP
commonly uses ICMP and default routes to determine interface failure
states thus it well suited for a NAS protocol service layer. In a
effort to reduce excessive ICMP rates we will aggregate the two dual
interfaces into a single channel connection to each switch. This will
allow us to define two test IP addresses for the IPMP service and keep
our logical interface count down to a minimum. We are also defining a 2
port trunk/aggregate between the two physical switches which provides
more path availability and reduces switch failure detection times.
- Hany Michael – vSphere In Motion: A Real-World Live Migration Scenario
I was having a discussion with one of the large enterprises here in
Qatar lately, and I was quite surprised to know from them that they are
hesitated to migrate their VI3.5 environment to vSphere because of the
associated downtime. What surprised me was not the fact that they can't
afford a downtime, I've spent 6 years of my career working in the
Telecom sector and I know for a fact that 1 second of downtime could
mean a disaster, or even translate to a loss of thousand of $$. What
surprised me was that they didn't know that it is possible to do this
migration without any downtime!
- Scott Drummonds – Inaccuracy of In-guest Performance Counters
Every couple of months I receive a request for an explanation as to why performance counters in a virtual machine cannot be trusted. While it is unfairly cynical to say that in-guest counters are never right, accurate capacity management and troubleshooting should rely on the counters provided by vSphere in either vCenter or esxtop. The explanation is too short to merit a white paper but I hope a blog article will serve as the authoritative comment on the subject.
- Bouke Groenescheij – Removevmha
Today I've updated the popular removevmhba script to version 5.0. This version now includes the removal of the drivers in vSphere ESX 4.0 update 1 isos. Thanks to Dinny Davies who did excellent work again on finding a solution for removing them on vSphere ESX4 (he just beat me to it Wink). Check the original ESX 3.x.x version here, and the new ESX 4.x.x document here. Go ahead, grab removevmhba from the downloads section and give it a try. It removes the drivers only during installation, so you don't need to bother disconnecting your SAN or zone out anything during installation (both Emulex and Qlogic – and also hardware initiated iSCSI adapters). It's much safer for a scripted installation of ESX using the UDA or EDA. After the installation you will have the drivers (since it is installed as a package) – so you will get connection back to your SAN.