Les Mikesell wrote:
On 6/29/2011 4:04 PM, Emmanuel Noobadmin wrote:
On 6/30/11, Les Mikeselllesmikesell@gmail.com wrote:
The seriously on-the-cheap approach is to run a few virtual servers on hardware slightly better than one of the individual servers would need.
Actually THAT is the fundamental problem ;) The physical server is frankly much more powerful than the two guest running on it. I have the same applications + public web/email running on old dual core machines with less memory than the guests.
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OK, but without knowing the cause, you already know the cure. Make the virtual servers not share physical disks - they will always want a single head to be in different places at the same time. And there is also probably some ugly stuff about how using files for virtual disk images and perhaps LVM on both the real and virtual side makes your disk blocks misaligned. Fixing that might help too.
Here's another one, that I got from another admin talking to VMware: watch out just how many virtual CPUs you assign to each VM. If you've assigned 4, it is actually going to sit there waiting until it gets 4 virtual CPUs. As of '09, VMware was recommending assigning 2.
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