whats the point in vm?

Just wondering but what is the point in server virtualization? After reading a few threads I've noticed people are running vm's of this server os and that server os. I'm in the dark here and trying to figure out why to educate myself but the only reason I could see is if you like a Linux app and you run a Windows OS so you could dual box them at the same time. Beyond that, whats the point?

To actually make use of the hardware thats available today. Cut down on hardware and energy costs, etc.

It is real handy if you have a bunch of stand alone servers that aren't running at 100% all the time. If you get one big beefy box you and put on ESXi or Hyper-V and visualize those boxen under one hardware platform and save power consumption and overall hardware costs.

The fancier implementations of ESX support VMotion which is purt near handy.

Checkout http://www.youtube.com/watch?v=E_TtHAgRy_s. Pretty nifty.

density, performance and manageability.

On larger scales...you can get redundancy. Split the load of many virtual servers to several physical servers...if one physical server is experiencing hardware problems...you can "move" the virtual servers it was running "on the fly" to another running host box...so that you don't experience the downtime.

The above makes for easy replacement of hardware too.

Also you can more easily "test run" certain servers...without investing in further hardware.

I use Hyper-V under Win2K8 for prototyping stuff. Working on automagic installation of code using NAnt and it is great to be able to fire up a VM, take a snapshot and test the rollout that does all the configuration settings.

If something is wrong and needs to be tweaked, I roll back to the previous snapshot and fix and twiddle and fire off again. I find that is my particular advantage in using Hyper-V VM.

instead of 50 different app server boxes running on janky hardware at less than efficient utilizations,
a smaller number of easily maintained and expandable uber boxes with a higher utilizationr rate.

you can allocate CPU and memory dynamically as load changes.

The short answer is to make better use of the resources you have (Increased ROI). The long answer can include many different things:

Decrease hardware cost
Increase hardware utilization
Decrease cooling requirements
Decrease energy usages
Decrease data center footprint
Increase uptime
Increase fault tollerance/redundancy
Increase flexibility
Increase security

The reason to use virtualization will vary depending on the organization or person and what their goals are. These goals will also dictate which options are used. A developer might use VMware Workstation locally to test code because it increases their flexibility in testing different platforms while and enterprise as a whole might use VMware Infrastructure to achieve maximum ROI and minimize downtime. Both are virtualization, but are different implementations of it.

a bunch of VMs with one app per OS has better performance than one OS running all the apps?

If the computer is powerful enough to run a bunch of VMs for all the servers you had, it should be powerful enough to have all those services within one OS (or two).

Cheetoz said:

a bunch of VMs with one app per OS has better performance than one OS running all the apps?

If the computer is powerful enough to run a bunch of VMs for all the servers you had, it should be powerful enough to have all those services within one OS (or two).

Click to expand...

What happens when one of those service crashes the whole server or requires a reboot after updates? Separating the services can increase uptime. The answer to your question depends on the environment.

With virtualization, you can have a pool of hosts and distribute the load across them. If one host has a problem, then you move the VMs that it was running to another host so that you can resolve the issue. When the OS is no longer bound to a physical piece of hardware, flexibility of managing those hosts can be greatly increased.

Cheetoz said:

a bunch of VMs with one app per OS has better performance than one OS running all the apps?

If the computer is powerful enough to run a bunch of VMs for all the servers you had, it should be powerful enough to have all those services within one OS (or two).

Click to expand...

not all apps play nice together. not all apps share resources elegantly. everytime one app goes down, it might take down the os. everytime you have to patch or update a broken app, everything goes down. if something happens to your OS, all the apps break.

1 egg in 1 basket at a time, instead of all eggs in one basket, also VM baskets are easy to increase or decrease the size of the basket

MorfiusX said:

When the OS is no longer bound to a physical piece of hardware, flexibility of managing those hosts can be greatly increased.

Click to expand...

/thread

Also education. My 2003 server classes use VMware to set up our own networks to play with. At home, I can set up the exact same setup I have in class and add more complexity to my network if I want. All without having to buy any hardware.

Repairing a guest OS is also easier. No troubleshooting required.. just rollback to a previous snapshot.

so instead of saying running dns on one srver and then AD on another you run one machine with 2 vm's with the same configs. That way if one goes down and you have another system it will switch over the vms to another machine so nothing goes down? I get why to do it but I don't see how its done.

Destonomos said:

so instead of saying running dns on one srver and then AD on another you run one machine with 2 vm's with the same configs. That way if one goes down and you have another system it will switch over the vms to another machine so nothing goes down? I get why to do it but I don't see how its done.

Click to expand...

Just judging by your questions, I would suggest looking into the VMware Infrastructure system. There are quite a few things that comprise the total solution and there is way more to it that can be properly explained in a few forum posts.

But the idea for fault tollerance is this: You have multiple host machines (physical machines). These host machines can run a number of guest virtual machines. When properly configured, VMware Infrastructure can move a guest machine's resources between host machines. In the even of a host failure, all virtual machines running on that host are then automatically moved (restarted) on the remaining host machines.

Guest machines can pretty much by any OS/service that runs on the x86 architecture. This could be standard Windows Server, *Nix, etc. I haven't really found many things that can't be ran inside of a VM. Somethings do better than others, but that's another topic.

We have two dell servers both with 32GB ram in it. We are planning to run a whole bunch of VM on those things. We've already migrated couple of servers over. We love the backup process. Just load your VM image back into host machine and you are up and running in matter of seconds. The 2nd VM machine is designed to take over if the first one ever fails.

we have 6 vm esx servers right now. We run a lot of small utility servers on distributed between two 8 core, 24 and 16 gb ram, on a FC SAN. Things like, anti virus servers, blackberry server, some web servers, test environments etc. They are invaluable for testing environments. You can clone a server, apply the patch to the copy, and if it doesn't work, roll back a snapshot or bring up the original, in the pre patch state. We have our enterprise document management environment running across 2 vmware server, setup so if one fails, the other servers come up automatically on the other one.

With all the bells and whistles, it's a sys admin's dream. Even without all the expensive extra's, it's still really nice.
Plus with the new esxi free hypervisor, you can run it pretty cheap.

ok so I think I get it now.

physical machines running multiple vms on them with each vm's running services. one machine goes down the vm's on that machine are started up on another machine. Likewise, if a vm goes down on a machine the rest keep running and that vm is either restarted on that machine or brought up on another phsyical machine. More fault tollerance than having say 1 physical machine with all the services running on that machine.

Do you need a legal copy of each OS for each vm? I'm asking this because I'm trying to figure out how some stuff work in the real world as opposed to theory we have been learning here at college. I have 1 one semester left before I graduate with a major in Telecommunications Systems management with a area study in Sys Admin and Wireless tech.

I worked this summer at the 3rd largest bank systems and security company in the USA (CSI, Computer Services Inc.). I did Email tech support for POP3 and Exchange as well as Blackberry support through the companies BES. I had all the remote maangement programs I used in a vm on XP I would boot up on machines that I logged onto for the day because I roamed around the office depending who wasn't at their desk for the day.

I'm also interested in it because I'm going to be poor when I graduate college and I'm trying to see if its worth it to take my current rig (in sig) which is like 4.5 years old and run a vm on it taking 1 gig of its memory and turn the VM into a file server while the main OS runs untangle. Might pop some more ram into it and see about running a linux OS as well to fiddle around with it.

Yes, you will always need a legal copy of anything you will be running be it in a test or a production environment. While you're a student you should look into getting academic versions of software or try getting a technet or MSDN subscription.

we have msdn on campus. The Xp I have installed on my machine right now is legit but its a student copy so its 1 license only and can't install on multiple machines. It was completely free and I haven't been able to obtain any os's since. I'm going to talk to my professor in telephony wednesday about getting server 2003 and maybe a 32 copy of vista just so I have another OS. If need be and I get in a corner I'll run a linux client for untangle in vm .

Destonomos said:

we have msdn on campus. The Xp I have installed on my machine right now is legit but its a student copy so its 1 license only and can't install on multiple machines. It was completely free and I haven't been able to obtain any os's since. I'm going to talk to my professor in telephony wednesday about getting server 2003 and maybe a 32 copy of vista just so I have another OS. If need be and I get in a corner I'll run a linux client for untangle in vm .

Click to expand...

You might check out the Dreamspark project from Microsoft. You can get a free copy of Server 2003 Standard (or other dev. apps, etc.) as a student.

https://downloads.channel8.msdn.com/

As far as VMs, some people pick-up the concept very easily, while others take quite a while to wrap their head around the idea. Stick with it, and I think you will be very impressed.

I signed up for dreamspark and I did the verification thing through journeyed.com. How long does it take for me to get my email so I can download server 2003?

I think it can take a few days for them to verify the info.

Sweet. I'm downing Vmware Server 2 now and Cent OS. I've been wanting to play with a linux OS for shits n giggles for some time now.

sweetness I'm posting from my vm in cent os .

Destonomos said:

ok so I think I get it now.

physical machines running multiple vms on them with each vm's running services. one machine goes down the vm's on that machine are started up on another machine. Likewise, if a vm goes down on a machine the rest keep running and that vm is either restarted on that machine or brought up on another phsyical machine. More fault tollerance than having say 1 physical machine with all the services running on that machine.

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If the physical machine goes down then you are F***ed. The biggest advantage is being able to throw a VM server together quickly to host those lame ass legacy applications and small apps that need to be made available without having another physical machine.

Destonomos said:

I'm also interested in it because I'm going to be poor when I graduate college and I'm trying to see if its worth it to take my current rig (in sig) which is like 4.5 years old and run a vm on it taking 1 gig of its memory and turn the VM into a file server while the main OS runs untangle. Might pop some more ram into it and see about running a linux OS as well to fiddle around with it.

Click to expand...

Get a credit card 0% offer and update that shit dude! You will need it.

calikool said:

If the physical machine goes down then you are F***ed. The biggest advantage is being able to throw a VM server together quickly to host those lame ass legacy applications and small apps that need to be made available without having another physical machine.



Get a credit card 0% offer and update that shit dude! You will need it.

Click to expand...

First off I don't need to do that because I already have 3 credit cards that I've been using to build my credit scores with. I've probably put over 10k in stuff on them while I've been in college. My credit score is like woah right now . I doubt very seriously that I will need something stronger than what I have right now once I graduate college. I don't play games on my computer very regularly anymore. I play TF2 right now it runs fine at 30 to 60fps at medium to low settings and is very stable.

Only thing I'm doing right now to learn some stuff is messing with vm's and gns3. I don't see the point in upgrading right now. Maybe a year or two after college once I've saved some money I might get a badass PC and turn this into an untangle and server box like I said but until then its going to be my main PC. I might get rid of the 5.1 system I have right now because it's getting on my nerves and get a nice 2.1 setup and replace my monitor which is aging and actually started messing up this last month with 2 LCD's for desktop work and stuff.