Storage

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  • 1.  RAID 0 Question

    Posted Jun 15, 2011 02:37 PM

    I've looked through existing discussions both here and on other sites, but have been unable to find an answer.

    I have a laptop with 12GB of memory and 3 identical 500GB 7200 internal drives, two of which are combined into a 1TB virtual drive using RAID 0.  I know that any VMs should exist on a different physical drive than the host OS for drive I/O performance.  My question is: would I see the best performance using the RAID 0 for the host OS, or for running VMs?

    I understand that RAID 0 performance gains are dependent upon stripe size vs. how it’s used, and are not always consistent, but it would seem that the RAID drive should be utilized where the most disk I/O is present.  Having plenty of memory, caching is not an issue, so I guess it boils down to how VMware Player works with disk space.

    If the answer is already out there somewhere, would someone please direct me?

    Thanks



  • 2.  RE: RAID 0 Question

    Posted Jun 15, 2011 03:37 PM

    Disk performance is a big thing. I have really found that out with VDI. I would imagine that if you put your VMs on the RAID 0 partition you would get much better performance out of them. Just keep in mind that if you lose one disk you lose all your VMs. With that in mind why not just put your VMs on a SAN or NAS. You could put the ESXi OS on the RAID 0 partition, but I don't think you would get the same performance boost as you would by putting your VMs there. Try it out and let everyone know.



  • 3.  RE: RAID 0 Question

    Posted Jun 15, 2011 04:07 PM

    Thanks, for the reply.  Ultimatley, I would like to set up RAID 10 on the drive pair, but the RAID 0 question seemed like the first logical step.  I have lost data in the past and am borderline paranoid, so I always keep detached backups as well, no matter the built-in redundancy... it's only space, after all.



  • 4.  RE: RAID 0 Question

    Posted Jun 15, 2011 04:10 PM

    If you are looking for max performance why not put your OS for your host on flash and then use SSD for your VMs. That will give you good performance. I just don't really like using RAID 0.



  • 5.  RE: RAID 0 Question

    Posted Jul 30, 2012 03:54 PM

    Well, it's been a year, and I just wanted to report on what I've done and how it's worked:

    1)     I ended up running the VMs from the RAID 0, and the host OS on the stand-alone drive.

    2)     I chose to keep the host OS rather than using EXSI so that I would still have access to the hardware features available that came with the laptop,         regardless of whether or not they are supported by VMware.

         a)     This turned out to be a good decision as some uses such as online gaming and audio and video applications have issues when executed from              within VMs.  For these things, I use programs from the host as opposed to running them in a VM.

    3)     The applications running in VMs from the RAID 0 perform nearly as well as if they were running directly on the host OS.  I am a software         engineer/developer so responsiveness while working with development and office applications is crucial.  I have been very pleased with the         performance of the VMs, and have had no issues with anything not running smoothly.

    4)     All of this being said, I do keep an external drive handy to which I make regular backups of my VMs in the event that one of the RAID 0 drives         should fail.  This is the "Achilles' Heel" of my set-up and until I invest in a laptop capable of supporting a minimum of a 1T RAID 10, I will always         have to be prepared for the total failure of my RAID 0.

    I hope this helps anyone else who may be looking for guidance in making similar decisions.



  • 6.  RE: RAID 0 Question

    Posted Jul 30, 2012 04:11 PM

    Thanks for the post,

    what kind of laptop has 3 internal drives?

    that must be big!



  • 7.  RE: RAID 0 Question

    Posted Jul 30, 2012 04:47 PM

    http://www.msi.com/product/nb/GT683.html

    I had it customized to replace the blue-ray drive with a third internal HHD