Announcement

Collapse
No announcement yet.

The point of virtual servers

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • The point of virtual servers

    In the office we were talking about virtual machines/servers and they use, but we couldn't come up with a reason why a company would want to use virtual servers.

    So i was wondering if people could tell me why you would run a farm of these things, the advantages, disadvantages etc

    Regards

    Dave

  • #2
    Re: The point of virtual servers

    Easy - hardware cost.

    On a good powerful ESX box with 8 dual-core, hyperthreading processors and 64Gb RAM using high-speed SAN storage you can probably host 15 good-spec servers, each running its own OS and hosting its own applications or even file and print. One box of a suitable spec might cost GB£30,000 - which is considerably cheaper than the 15x GBP4000 you would need for 15 separate boxes of a reasonable spec to run the same environment.

    It's not suitable for all environments nor is it suitable for all applications - but speak to your software vendor(s) and ask them if there is any benefit to virtualisation of their app.


    Tom
    For my own and your protection, I do not provide support by private message under any circumstances. All such messages will be deleted and ignored.

    Anything you say will be misquoted and used against you

    Comment


    • #3
      Re: The point of virtual servers

      Dave,

      I ran into the same issue on trying to justify the cost and why we should go virtual. I ended up going to VMWare's website and found a TCO Calculator. It will take an estimate of what you are currently running and will be implementing in the next x years. It then calculates the cost of individual servers VS a virtual environment.

      The TCO Calculator justified itself for our company and I have money in the 08/09 budget to go a virtual environment

      Also an advantage with going virtual is when running VMWare with the ESX Boxes connected to a SAN is the ability to have DR and High Availability. If an ESX Box goes down, in a properly configured environment another ESX box will pick up the load. That is just one of many things that VMWare Virtualization can do.
      Hope this helps.

      Nate

      My advice is provided AS IS, without warranty of any kind, express or implied. Follow at your own risk.

      Comment


      • #4
        Re: The point of virtual servers

        Ah ok, makes a bit more sense now. We didn't have a specific use in mind, it was just one of those things you have a quiet period and it pops up as a question.

        Just looked at that VMWare thing and thats pretty good, will have a look at that.

        So would you say they is a minimum limit to how small your server farm needs to be for virtualisation to become viable?

        Dave

        Comment


        • #5
          Re: The point of virtual servers

          Dave,

          I think there are a number of advantages to going virtual:

          Cost - In a large organization the cost savings just in hardware and hardware maintenance can usually be enough to justify using virtual servers. This doesn't even take into account the reduced costs for electricity (fewer servers and less air conditioning) and the reduced footprint in the datacenter. The hardware savings are not limited to the servers but can also be seen in reduced infrastructure costs (fewer servers mean fewer switch ports, fibre cards, UPS systems, racks).

          Disaster Recovery - If setup correctly virtual servers can greatly improve your ability to recover from a disaster.

          Rapid Provisioning - I can deploy a new VM in less than an hour on my ESX farm where I used to have to wait several weeks to receive hardware and then do an OS install. Most people don't factor this in and it can make a huge difference to your business units when they can get the servers they need in 1/20th of the time that it used to take. This can dramatically affect project roll out schedules.

          There are also some cons to going virtual:

          New Technology - VMware is a new technology that will need to be learned by in house personnel or new personnel may need to be brought on to manage the ESX farms. There may also be resistance from application owners who do not understand virtualization and therefor fear it.

          Server Sprawl - Once we installed our ESX farm and divisions found out how quickly and easily they could get new servers the demand for new servers went up dramatically. Many of the costs associated with physical servers are still there for virtual servers (i.e. monitoring, patching, backups). We were able to reduce this issue by implementing charge backs for virtual servers. They were still cheaper than physical servers but the departments had to come up with some money to justify purchasing new VMs.

          Upfront Costs - Depending on your situation there can be a lot of upfront costs associated with going virtual. You may need to purchase several higher end servers, SAN infrastructure, and disk storage. These costs can be very high but they can usually be recovered in a relatively short time frame.

          Thanks
          Rob

          Comment


          • #6
            Re: The point of virtual servers

            Originally posted by DaveUK View Post

            So would you say they is a minimum limit to how small your server farm needs to be for virtualisation to become viable?
            As for a recommended minimum not really sure. I have talked with some VMWare Rep's and listed our 15 servers and their roles and they said virtualization would be viable. This could have come mostly from a sales stand point but after researching I believe it would be a vialble solution for our 15 servers.

            Rob lists alot of good points about virtualization also.
            Hope this helps.

            Nate

            My advice is provided AS IS, without warranty of any kind, express or implied. Follow at your own risk.

            Comment


            • #7
              Re: The point of virtual servers

              One thing not mentioned above is points of failure. If you have only 15 servers I would not even consider virtualising down to one single machine - if a crash occurs or if faulty memory strikes then all 15 machines are instantly offline. I would only consider virtualising a percentage of your estate and that to be distributed across several physical boxes, and never (obviously) have more than one node of a cluster on a single physical box.

              If you have databases and database apps then have the App server on a separate physical box to the database server, and have the data separate again. Always look for the places where you have a low number of (or single) failure points and avoid them like the plague where it's physically possible.


              Tom
              For my own and your protection, I do not provide support by private message under any circumstances. All such messages will be deleted and ignored.

              Anything you say will be misquoted and used against you

              Comment


              • #8
                Re: The point of virtual servers

                1. redundancy

                2. managability

                3. ROI

                4. virtually no down time (no pun intended)

                snapshots rule. its nice to try an unremovable update on an isolated clone than a production server.

                DRS clusters rule. you know a web server is never gonna max out its resources (in most scenarios) and is really limited to bandwidth, so letting ESX manage the needs of my four webservers is nice.

                vmotion rules the hardest. i can flip-flop servers from the DR colo facilty to our main office and the clients see no change.

                i have a sun solaris 5.8 box. the mantainance fee for the box was 6K a year. now that the life is up on the server, the cost shot up to 25K... needless to say, i virtualized it, and now the yearly maintance fee is zilch. in a 3 year ROI investigation, this will save us over 60K on a box that is only accessed by 30 or so people. do the math...

                right now, the only thing i have not virtualized is my back end exchange server. the front ends are a prime virtualization canidate. i didnt move the mail stores due to fiber zoning and such, but i would consider having my exchange server on a VM...

                in all, the good chunk of moneyz you spend on ESX will pay for itself in ROI for an IT staff with limited workers.

                at my job, me and my partner manage about 55 servers both virtual and stand alone... but i can tell you that each week that goes by, there is a new virtual being migrated.
                its easier to beg forgiveness than ask permission.
                Give karma where karma is due...

                Comment


                • #9
                  Re: The point of virtual servers

                  There is another reason that I haven't seen posted here...

                  Now we don't do this but I know that some shops do....

                  How much time do you spend building a server going through custom settings to get it working just right in your environment? Then a couple years goes by and there is no need to really make any changes to the server other than the equipment is now out of warranty and it is a critical system. If it is running on a VMWare type system you can buy a new physical box load it up with the host OS and migrate the Virtual Server over to the new box and keep on chugging along. I know that there are shops out there that do just that when they have a VMWare environemnt where a host only has one guest on a physical box.

                  The where you pick up gain in the resources is that if you were to look at any of your traditional servers. I would doubt that any of them are pegged as far as resources. By consolidating the machines down using this technology the amount of the resources you are actually utilizing will increase and that is where the cost savings comes in.

                  As for us we have about 60 guest machines running on 4 ESX servers. We are running ESX 2.5 and are in the process of buying new hosting server to replace them that will run VI3. We are looking forward to using VMotion and the other features of VI3
                  We do have one machine that is our first venture down the path of Virtualization that is running the less advanced GSX version. While this is fine the problem with it is that we used Windows Server for the host. So whenever Microsoft releases a patch we are forced to bring down the host and therefore all the guest machines. We will continue to use the GSX platform (now called VMWare Server) for our QA environment. We will be rebuilding these machines so that the host is running Redhat though. This will give us a more reliable platform for it. We want to use the free VMWare server for this because it does not require the expensive licensing.

                  VMWare Server is a great way to get a feel for vitalizing things. Take an old retired server and start playing with it.

                  Comment


                  • #10
                    Re: The point of virtual servers

                    If your company wants close to 100% up time, then a VI3 Infrastructure is what you should be looking at. Being able to move servers while they are "hot" is heaven-sent. HA lets systems admins sleep better at night. If your virtual host server in a cluster takes a hit, all its vm's will be restarted on other cluster nodes, etc..

                    We have a big DR plan, with the combination of Virtual LANS, Virtual Servers, and Virtual Storage, we are able to replicate and bring up any one of our remote offices at the data center if disaster would strike.

                    Image this, your building management sends out a email/letter stating they are conducting a power test all weekend long... Well with my Virtualized infrastructure, I dont have to worry. I can simply pick a time on Friday night to down all servers (15+) for about 1hr. while I make the final replication sync's, flip the vlans and crank up the virtual servers on a standby box I have waiting out at the data center... You can repeat the steps to go backwards at any given time when the "all clear" is given.

                    Try that with a physical environment..

                    Comment

                    Working...
                    X