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I decided recently that since I virtualize all my programming environments there is basically no reason for me to be running Windows as a host OS. So, to get me started I installed Ubuntu via wubi and am happily dual-booting to it. From inside I can use virtualbox to access my windows 7 VM and start it up to develop in.

It's not particularly slower, but not any faster than it is on the Windows host and I wonder if that is because that's as fast as it's ever going to be on my hardware or because wubi still runs on top of windows.

Basically, I'm unclear on how exactly wubi works and what if any performance hits using it entails.

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up vote 2 down vote accepted

IIRC Linux installed via wubi does not run on top of windows at all, it just runs from a "virtual disk" file in the Windows filesystem. Therefore you will not see any performance degradation such as the hit in I/O performance common with some virtualisation solutions.

There will be a slight hit has all access to the vdisk files have to go through an extra filesystem layer, and the vdisk files may themselves be fragmented as well as the contents, but for many I/O patterns you will not particularly notice this.

So Windows in a VM running under Linux booted from a wubi based setup is likely to run very nearly as well as if Linux were install on it own physical partitions. If you do notice any unexpected performance drop, or if you end up wanting to remove the Windows host OS completely, it is possible to migrate a wbui install to direct physical partitions.

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Thanks a lot, the next step is to get a hybrid ssd, move my current windows install into a VM, install Ubuntu natively and run it that way – George Mauer Jun 29 '11 at 21:51

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