Musings of a sysadmin
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Transcender sale 20-21 oct 2009
0839 days
by admin
in Uncategorized
I have just had an email come in saying that transcender are have a 40% off sale on all their items for 2 days only.
You may remember that I reviewed a transcender product not too long ago and it came out very well against the product I had normally used. So if you have not used transcender yet now is a good time to give them a go.
www.transcender.com
Virtualizing Linux OS
0844 days
by admin
in Uncategorized
Just a quick observation considering vmware has a linux based service console and lots of options for new linux builds, its really crap at virtualizing physical boxes!
Learning Java the easy and fun way
0857 days
I was flicking through the usual linux mags I buy the other and came across a link to a java learning tool called Robocode. Its basically a java game where you can pit your tank against others (either the default’s or the ones that other people have written). There are a good number of tanks to choose from to start with and then you edit the code to improve your tanks abilities.
HA Host Isolation Response
2860 days
Host isolation is basically a state that a host in an HA cluster can reside in should it detect a loss of network connection. However there are a good few things to know about this feature. When a host is in a HA cluster it sends out a heartbeat to other hosts in the same HA cluster. This enables the cluster to detect when a host has failed and power on the VM’s that it was running should that be the setting you choose.
Firstly the Automated Availability Manager (AAM) controls the heartbeat process through the Service Console and its configured address.
However this alone presents itself with a problem. If you only have one Service Console installed on a host it is possible that AAM will think a host has failed when in actual fact a failure has only occurred somewhere on the path from the Service Console mapping to the physical NIC (uplink) and outwards. With a host that has multiple uplinks (a full blown ESX Production server will need at least 3 or more) It could mean that the Virtual Machine port group on another physical NIC could be happily working away.
After 15 seconds of missing a heartbeat response each node will ping the default gateway for its service console (this is called the Isolation Response Address). This is basically the hosts way of saying “is this problem my fault”. If the host receives a response from its default gateway it carries on as normal as the fault is not with the host. If the host however does not receive a response it will go into isolation mode.
The host(s) that enters isolation mode would then read their isolation configuration which will tell the host either to power off the VM’s or leave them running.
The correct configuration for this setting relies pretty much on you network. If for example you have a vswitch configured with a Virtual Machine port group and the Service Console port group then as you’ve lost your Service Console you’ve also lost your VM network too so you will want to power the VM’s off and let HA bring them all back up again on other hosts. However if your network is redundant enough loosing a service console isnt really a big thing if your Virtual Machine and Vmotion networks are still working.
It is considered best practice to have 2 Service Console’s configured per host on different vswitches,vmnic’s and physical networks. this sounds a bit complicated but when you consider that Vmotion should really have its own dedicated physical switch and subnet then the choice on where to put the Service Console suddenly becomes very clear.
In the Next blog I will talk about the actual steps you need to take to configure Host Isolation and a few extra switches that you may need.
VMware Install & config Course
0866 days
by admin
in Uncategorized
Hi all,
Well today was the first day of my install & config course. So far its nothing particularly new although it is good to meet with other IT bods and hear there views and experiences of vmware. I suspect that a few vmware releated posts will pop up.
Vmware install and configure course
0887 days
by admin
in Uncategorized
Hi all,
Work has kindly agreed to pay for my vmware course for me which is very appriciated. I wanted to do the course so I can take the vcp exam and become a vcp.
There is alot of cool stuff to learn in order to pass the exam and I am quite sure that virtualization is the way of the future so it will help me imensely if something untoward happens to my job (I doubt it but you never know).
Also I discovered that if i get my skates on I can also take the vsphere exam before the end of the year without having to go on another course. I doubt I will get round to it as my open university course also starts soon so I think I will be a busy boy for the next few months. Still strings to bows.. Strings to bows!
ESX 3.5 Evaluation
0900 days
by admin
in Uncategorized
Hi all,
As stated in my previous posts im looking to set up a lab for ESX which involve using the vmware server for windows xp to virtualize ESX boxes plus setting up some ISCSI Luns on freenas for storage. However looking at the vmware site I thought my plans were dashed before they had even started. Any mention of ESX 3.5 eval versions had disappeared and naturally been replaced by vsphere evals. Bugger thinks I, so I put up a post on VMware communities and some bright spark told me to sign up for an evaluation of vmware view and because it only works on on ESX 3.5 they provide you with trials of ESX and virtual center as well. So I hot footed it to the viewer page and signed myself on to an evaluation, sure enough there were the ISO’s for ESX too.
Marvelous isnt it!
ESX in ESXI
0905 days
by admin
in Uncategorized
Right I’m looking for ways to virtualize ESX within an ESXI server or maybe even vmware workstation. Any ideas anyone.
Virtualizing linux boxes
0913 days
I’m going to talk briefly about virtualizing live linux servers. At work i’ve just virtualized my first red hat box. Was it painless? No. Was it informative? Yes.
l was given the task of p2v’ing the box after a disk in its mirror failed. So with a good bit of googling i came upon this tutorial on how to virtualize the box. It was not quite complete for me and I had to figure out various error messages I encountered along the way but I eventually managed it and with shaking hands clicked the vm’s power on button.
I must admit I was expecting a good number of errors when it started (and would not have been surprised by a kernal panic), but it booted into kudzu hardware manager uninstalling all the old bits and installing the new and too my relief completed its boot without any further issues.
Some of the issues that I came across along the way is doing the conversion in this way creates a VM for you and it firstly mounts a VM convertor helper ISO into the VM. This helper VM requires an IP address etc so you need to either let it DHCP for an address or Statically assign one during the convetor wizard screen.
Also as it needs to be contactable on the network you need to ensure that the VM is set up so that the network card(s) are on your production network. So if any of you normally put the cards into an isolated lan then this wont work. Also I’m not sure if this is to do with our setup or convertor “feature” I found I had to have the machine running the convertor client connecting to the convertor server on the linux box in the same subnet.
Trouble is now I’ve done one I expect I’ll be labelled with the “Linux Virtualization Expert” badge at work and will be given lots of other jobs that wont be quite so smooth! Ah well its all about the learning curve isnt it.
Open University
0926 days
by admin
in Uncategorized
Not a particularly interesting post but my login details for the OU came through the post today. I also found out that there is a couple of courses that you can sign up for and send your Microsoft transcript to them and you get points towards whatever academic qualification you are looking to pursue at the OU.
Details can be found here.
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