Virtual Conversions

  • Bob Lee (7/24/2008)


    And I'm curious about the folks who moved to the VM servers. Exactly how did you do your load testing?

    Load testing? What's that? 😀

    Seriously, we didn't do any. We knew enough to know that it would work. When we started the conversions, it was gradual and during real work loads so we could watch how the physical ESX server was responding to the load. If I recall correctly, we were told we could allocate 150% of the processor and memory since ESX would take care of moving things around as necessary. Ultimately, our decision was to allocate no more than 80% of the processor and memory which still left room on two physical ESX servers to run over 60 VMs.

  • I'm a big fan of using some type of VM for taking a production environment to use in a development environment. That way, there would be up to date data that closely approximates the production data for developers to use. Also - while the physical environment would be different, the rest would be a very close representation to production - and would be easy to get a fresh snapshot.

  • Our state is moving to virtual servers at a very fast pace. So far they have virtualized about 150 servers, many of them production SQL servers. They have only had minor glitches a couple of times.

    I'm still waiting to see how they handle one of our servers, which has a specialized hardware storage card attached (it gives us the ability to address multiple terabytes as a single drive letter).

  • Charles Cherry (7/24/2008)


    Our state is moving to virtual servers at a very fast pace. So far they have virtualized about 150 servers, many of them production SQL servers. They have only had minor glitches a couple of times.

    I'm still waiting to see how they handle one of our servers, which has a specialized hardware storage card attached (it gives us the ability to address multiple terabytes as a single drive letter).

    If you need that much space, this would probably be a good candidate for leaving as is. Does it have a lot of traffic? Another thought would be to move all of that storage onto a SAN attached to the virtual server but I suspect that you may be looking at diminishing ROI.

  • Ah guys sorry I don't get the question about moving from virtual to physical servers....I'm not a network admin. 😉

    Can someone state the issue - are you gonna set up a VM instance with named virtual hardware and then try and replicate it for real?

    Why would anybody do that? Please explain it to me.

    Hiding under a desk from SSIS Implemenation Work :crazy:

  • Shaun McGuile (7/24/2008)


    Ah guys sorry I don't get the question about moving from virtual to physical servers....I'm not a network admin. 😉

    Can someone state the issue - are you gonna set up a VM instance with named virtual hardware and then try and replicate it for real?

    Why would anybody do that? Please explain it to me.

    One thought I had when we started doing this was to make sure we could move back in case the load increased too much for the VM to handle. Or, if we determined that converting to a VM was a bad idea but too much data had changed on the server to easily move it back to the physical hardware (I know backup/restore **should** be fine but you would likely need to take the server off line to do this). Finally, being able to build and test before rolling out to production. In testing, it may work great but you know in production, you need dedicated hardware to handle the load. How about imaging?

  • This topic is very interesting to me, in fact I've already posted a message about it on this site's forums. My biggest concern is, should we be putting our production SQL Server database onto a VM? If you look at the topic I started, it seems to me that there isn't a consensus on this; some say it is OK to run your production databases in a VM, others say you shouldn't.

    I will be following this topic closely to see whether or not an consensus is arrived at here.

    Kindest Regards, Rod Connect with me on LinkedIn.

  • We have all of our servers running on ESX and Vmware (only one SQL Server). Our SQL server has never experienced any problems (good thing too, it runs the db behind our helpdesk:w00t:) The server that runs our order management system started to turn itself off every few hours. We weren't sure what was happening so we moved it (as users were still entering/processing orders) to anothe ESX and it hasn't had any problems since - I'm not a sys admin or anything, but I think that is pretty cool!

  • We were initially promised a SAN for our storage needs (we have a custom-built document management system that stores millions of tiff images), but central management couldn't get the SAN infrastructure in place fast enough.

    I'm not sure how they did it, but by adding that IO card to an old Win2K server, we have four terabytes available as a single drive, and it works great. They claim that by the time we fill up the four terabytes they will have figured out and installed all the other stuff (probably sometime next year).

    I'm not a hardware guy so I have no idea how they are planning on handling the virtualization of that server, or whether it is even possible with that specialized IO card. I suspect they guys doing the virtualizing are scratching their heads about, too.

  • We've just begun investigating this and have three servers for ESX along with about 10 TB of two new SANs for it. We have a lot of servers we can consolidate, both SQL and file/print, and some of them are quite wasteful: we just got a new system in for one database of about 200 meg running on an eight core server. Total hardware overkill. Then on the opposite end of the spectrum we have one box running NT 4 Server and Oracle 7.

    We're really looking forward to it.

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    [font="Arial"]Knowledge is of two kinds. We know a subject ourselves or we know where we can find information upon it. --Samuel Johnson[/font]

  • I forgot another comment that I meant to reply to. Some costs can be hidden and quite high: a lot of the servers sitting in your rack might have licenses that are bound to the hardware, meaning you'll have to buy new copies of the server OS before you can virtualize it. I hadn't considered this until our network guy mentioned it yesterday.

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    [font="Arial"]Knowledge is of two kinds. We know a subject ourselves or we know where we can find information upon it. --Samuel Johnson[/font]

  • That's just it. VM technology adds a level of complexity, but also a level of flexibility. For beefy dedicated servers, there's often nothing to be gained by slapping them on a VM and much to be said for keeping them stand-alone. For consolidation and portability, there's little to touch VMs, so the benefit is clear.

    As with everything, there's no one right answer; weigh up the benefits and the hassle factor and if the benefits come out higher, go do it.

    Semper in excretia, sumus solum profundum variat

  • Wayne West (7/24/2008)


    I forgot another comment that I meant to reply to. Some costs can be hidden and quite high: a lot of the servers sitting in your rack might have licenses that are bound to the hardware, meaning you'll have to buy new copies of the server OS before you can virtualize it. I hadn't considered this until our network guy mentioned it yesterday.

    Licenses bound to the hardware? I haven't heard of this outside of Apple. Our licenses with Microsoft allow us to move the OS and underlying applications to new hardware when we choose to replace it. Can you enlighten me (us)?

  • For Windows2008 you only need one server licence per physical machine.

    and if I'm not mistaken SQL Server is as well.

    So using HyperVisor you can have 4 WindowsServer2008 VMs each running SQL Server and you have top buy no extra licences other than 1 for the OS and 1 for the DB. 😀 all on the same box! 😉

    Hiding under a desk from SSIS Implemenation Work :crazy:

  • Almost all of our hardware is from Dell, and apparently the Windows Server software is bound to the hardware. It wouldn't apply if you're under a Windows bulk licensing agreement or if you buy your hardware bare and get the software separately. At least that's my understanding from what our network guy said.

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    [font="Arial"]Knowledge is of two kinds. We know a subject ourselves or we know where we can find information upon it. --Samuel Johnson[/font]

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