You're in trouble MGB...
Cyan~Fire - Thu May 04, 2006 2:37 pm
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I don't quite get virutal servers. You'd think that the extra layer would just slow them down a lot.
Cerium - Fri May 05, 2006 1:05 am
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Im sure it does, but its enough where its neglegable.
Mine GO BOOM - Fri May 05, 2006 2:02 am
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The only time being in a virtual server causes problems is when you try to go into the 0 ring on the processor, which is roughly raw access to everything. So a system call of printf() won't be effected, but using dd to wipe clean a hard drive will be effected. With most of the new chips being designed now, there will be a -1 ring, which is where virtualization software will be able to run at, thus you can have hardware virtualization happening where the kernel can run in ring 0 without being effected.
Simple way of thinking about it: if you are doing things as a normal user, virtualization is very fast as you just run natively on the processor. Doing some root things will be the only slowdown, and for almost everything on the server, you'll be running in user mode much more than kernel.
Cyan~Fire - Fri May 05, 2006 8:33 am
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I see. So virtualization just modifies the standard protection stuff like memory and all so that you can have multiple users running just like normal?
How does it work with CPU sharing, though? Does it use a rotating sort of system like Windows?