The VMguy » VirtualCenter

The results are in: Majority of my readers run vCenter in a VM!

The VMguy — Mon, 09 Mar 2009 17:48:09 +0000

I had the poll automatically complete last friday and here are the results: Of 110 votes cast by my readers, 57 of you said you run vCenter in a VM, 50 run it on Physical, and 3 don’t run vCenter at all.

Great information and thank you all that responded to the poll.

Note: There is a poll embedded within this post, please visit the site to participate in this post's poll.

New Poll: How do you like your vCenter? On iron or in a VM?

The VMguy — Tue, 10 Feb 2009 17:22:11 +0000

Posted a new poll this past weekend. I see some have already started responding. I know a few blogs have run this one in the past but I’m curious with my SMB focus to see if the results vary. Please take a quick sec and post a vote. I’m closing the poll on March 7th (an extra week because I started it late).

Just as a FYI, I run mine in a VM.

vCenter statistics settings

The VMguy — Wed, 07 Jan 2009 16:15:04 +0000

I’m a firm believer that better decisions are made with better information. When you open up the Virtual Infrastructure Client and select Administration/VirtualCenter Management server configuration. From there select statistics in the left pane. You will see a right pane that looks something like this:

By default, Virtual Center has set the statistics level to 1. The levels can range from 1 to 4. Level 4 maintains the most stats on your environment and is typically used for debugging. I do however believe that there are a lot of benefits to increasing that level to 2 or 3. For a great list of all of the performance counters that are available at each level, refer to this doc . This change can be done on the fly with no impact to running VMs. I cannot stress enough the value of the Database Sizer located at the bottom of the frame pictured. Once you have changed the statistics to the levels you are comfortable with, before pressing OK, plug your VM and host values into the sizer so that you know you will have enough room in your database. The last thing you want is to run out of room on your database server because of the expanded growth.

For specifics on the Keep For field, that really is how long the individual data points are kept or "rolled up". The real time stats in the performance graphs are not archived and are kept for the past hour. Past day stats take the real-time stats and roll them up so that there is 1 data point for every 5 minutes. Thus, there are 12 data points per hour and 288 per day. Past week stats take the past day stats and roll them up so that there is 1 data point for every 30 minutes. Thus, there are 48 data points per day and 336 per week. Past month stats take the past week stats and roll them up so there is 1 data point per 2 hours. Thus, there are 12 data points per day and 360 per month (30-day month). Past year stats take the past month stats and roll them up so there is 1 data point per day. Thus, there are 365 data points per year.

For more information, take a look at the Basic Admin Guide for ESX 3.5 starting on page 286 or the Basic Admin Guide for 3.0.3 starting on page 274.

VirtualCenter, run it on physical or virtual?

The VMguy — Tue, 11 Nov 2008 22:30:50 +0000

I get asked this question at least once a week. Should I run Virtual Center as a physical machine or as a Virtual Machine? The true answer is: either. I personally think it’s better to run as a virtual but it also depends on how comfortable you are with your Virtual Infrastructure.

You can run VC as a physical machine. Most of my larger customers run it that way. Their idea is that, "I don’t want to run my Infrastructure Manager in the Infrastructure it’s managing." I get that. It the previous versions, I might agree.

If I were going to build an virtual infrastructure today, I would run it as virtual. Here’s why: all the benefits of virtualization. For instance, I can take a snapshot of my VC server for Business Continuity and/or testing. I can have DRS balance my VC server on the infrastructure nodes that are most available. Most importantly, and one some customers don’t realize, is that High Availability will fully function. Even for the VC Virtual Machine itself. If the physical host where the VC server is running goes down unexpectedly, HA agents running on ESX itself will power on the VC VM elsewhere in the cluster. VC is only required to be running to setup and configure HA. Once configured, the agents running in ESX monitor and restart the VM’s in the case of a host failure. Of course, during the restart of the Virtual Center VM, DRS and VMotion will be unavailable during the boot cycle of the VC server. In my opinion, a small price to pay compared to the physical world. If VC were physical, how long would DRS and VMotion be down for? 30, 60 minutes while someone dialed in or drove in at 3am? In the virtual world, I could envision an outage of DRS and VMotion for 3-5 minutes while the VC server booted on another host.

Running VC in a virtual is not without it’s challenges. You have to manage the VC VM a little differently. To make changes, or move it, or power it down for any reason, you have to manage it from the physical host it is running on. So after powering the VC VM down, you have to connect the Virtual Infrastructure Client (VIC) to the host the VC VM was running on. From there you can make modifications to the VC VM, change the ram, power it on, etc. These are all things that are learned over time managing a virtual Infrastructure. If you’re not ready for that, you could start VirtualCenter as a physical server as as you become more virtual savvy, you can run the standalone version of VMware Converter to convert the VC server from physical to virtual. That’s always a possibility as well.

As always I recommend reading some documentation (RTFM) to fully understand this decision. VMware docs for virtualizing VC and all of it’s benefits and caveats can be found here .