One kink in the armor

If there is any issues with VI3, it has to be the reliability of Virtual Center after its host machine crashes.  In the past 2 years of running virtual center, the Windows box on which it runs has lost power due to facility issues maybe 5 times.  Of the five major power surges/outages, virtual center has failed to fully come online 4 times.  So far each time has required a reinstallation of the application, and a restoration of the last full db backup.  Luckily bringing the hosts back under management isn't a very arduous task.  Even without the database backup, you can still bring all of the hosts back under the VC umbrella rather quickly.  You do however lose all of your cluster configuration options.  This particular fault bit me just a few weeks back.

After a VC reinstallation due to a power outage, I had what I thought was a suspect database backup and current DB.  So I wiped the old db, and created a new one.  I brought all of the hosts back into management, but had forgotten about setting the DRS to partially automatic, rather than the default fully automatic.  This caused the VMs on my 75% utilized production cluster to start VMotioning at will about 3 every 2 minutes.  After about 40 or so vmotions in an hour, we finally had one puke.  Luckily it was our corporate exchange server.  After looking at the logs, and seeing all of the VMotions, it became clear to me that I had forgotten to go back in and setup all of the cluster settings as per my preference.  Once this was done, a VM reset, everything was fine.

Moral of the story, when recreating a VC database, be sure to go in and inspect all settings of a cluster, before re-adding the hosts!

Network Monitoring Utilities

Looking for a quick, cheap, simple network monitoring utility?  Who isn't?

I've tried a few different setups.  I've tried Netsaint/Nagios, Zenoss, straight MRTG, and now Cacti.  Nothing really has everything that I'm looking for in a peice of software to do this work.

What am I looking for?  Well I see two important peices to good network monitoring: trending, and alerting.  Some would say that the ability for the software to executre remote functions or scripts is also important.  Its important, however not in my top two.

Netsaint/Nagios - Nagios, the current product name, has been around for around 7 years or so is some version or another.  It meets both of the top level requirements.  It does a great job of service trending and alerting.  It is a bit weak on the network utilization trending, but you can always bolt MRTG onto the web interface and get something workable.  It has a great builtin web based data reporting interface, but can be quite cumbersome to get configured correctly.  It requires a lot of work with individual text files, profiles, templates, etc.  All in all, once its running its a great utility, but for those of us that have semi-dynamic networks it can become quite an arduous task to play keep up.

Zenoss - Zenoss is an open source project.  Zenoss like Nagios has a pretty impressive web interface, and is capable of both service trending, and alerting.  Through the use of some additional third party host agents, like informant, you are able to get quite a bit of data through the web interface with minimal customization.  The issue with Zenoss is its lack of simplicity.  The way that the graphs and hosts are displayed can be quite confusing, and at times almost impossible.  I do believe that with some tweaking of some of the web layout, and a few changes to the config, it could be a bit more user friendly.

Cacti - Cacti is also an open source project.  Cacti is extremly good at monitoring service trends as well as network utilization trending.  Basically, anything that you can point an SNMP query at and get a response, it can trend.  The only problem with cacti is that it doesn't alert, or I haven't found a way to get it alert.  The interface is awesome, and the graphing layout is totally customizable from within the application itself.  No Perl required!  Cacti runs on Linux, and is also available as a virtual appliance to run on most virtualization platforms.

All three packages have their strengths and weaknesses.  I personally like Cacti, and am looking for some type of bolt-on alerting module, as I believe it has the most intuitive interface, and is easily deployable on a virtual infrastructure.

Time is running out on Windows XP

Everyone knew that it would eventually happen, however for those of us that are purchasing Windows XP Professional licenses to run XP based virtual machines, this is a significant moment.  After 6/30/2008, many distributors will no longer be selling Windows XP Professional.  So if you are planning a VDI deployment using Windows XP Professional, you may want to get your OS licenses ahead of time, other wise you are stuck with Vista.  I do believe you can downgrade a Vista license to XP, but I am not totally sure of the process or if its actually possible.  I also don't know if this affects Volume Licensing customers as well.