jeff on 21 Jun 2008 14:02:47 -0700 |
Casey Bralla wrote: > I've been thinking about virtualizing on servers. Although I know that > virtualized servers are the "next big thing", I can't for the life of me > figure out the advantage for virtualizing servers, except for a few very > narrowly specific situations. Funny you should mention it.... I'm with consultants doing a `VMware Jump Start' last week and a bit next week. After that, we're gonna start going live. http://www.lockergnome.com/leftystrat This is my blog. Up at the top is a static page called Let's Get Virtual. It's the overview of our experience, filtered through my own uniquely skewed view. > This saves energy because a single fully loaded server > requires less electricity that dozens of partially loaded servers. Bingo. > maintenance, etc. (Cooling costs will only go down in proportion to > electricity consumption, so not as dramatic a savings there.) Going from about 20 to about 4 is fairly significant. > But why not simply run dozens (hundreds?) of server **instances** on the same > server? [guess] hardware isn't set up for it? Can you imagine running even *two* instances of 2003 Server on the same machine? > Why add the extra overhead of the virtualization process to the > hardware? That has to cut efficiency by at least a few percent. Processor horsepower has gone up dramatically. We're using servers with AMD's that are optimized for this. Technically there will be overhead, yes. This way is superior to the no hypervisor method (VMware player). Speaking of Player, I have run three instances of player on my main Xubuntu box at work with little CPU use. Starting them up sucked up resources but once they were up, they behaved. One pig of a client OS can make a difference (XP anyone?), depending on resources allocated. > So what is the advantage of running a complete virtualized server instead of > multiple server processes? Here's our decision path: Among our roughly 20 servers are at least 5 that are past end of life. After one month of monitoring, we found out we were only using something like 10% of our hardware. VMware has Magic Math<tm> that figures out from the monitoring how many servers to recommend for virtualization. I was skeptical (because I was awake) but the numbers have been verified independently and we're not exactly the first company to do this. When our numbers were plugged in to the handy TCO Analyzer, the three year cost of staying the same wildly trumped virtualization. The C*O hierarchy went right for it. Who was I to argue? > But other than this specific case, what the heck is the advantage? Hardware becomes standardized, which can be huge if you have to troubleshoot it. You can set up a totally separate lab environment. Backup takes on new dimensions. There are all sorts of interesting ways to do it. You can take an image of a running server and keep it offsite. How's that for disaster recovery and backup in one? With the copy, you can operate on live data without hurting the production environment. Need a new server? Provided you have the licensing, you make one from the template you create. If you want linux, you don't need licensing (evil and obvious laughter). In minutes. Presto. -=-=- ... Electronics Rule #2: never solder in shorts * TagZilla 0.066 * http://tagzilla.mozdev.org ___________________________________________________________________________ Philadelphia Linux Users Group -- http://www.phillylinux.org Announcements - http://lists.phillylinux.org/mailman/listinfo/plug-announce General Discussion -- http://lists.phillylinux.org/mailman/listinfo/plug
|
|