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Why is throughput to an external hard drive from a virtual machine much slower than through the host? Access is generally 30MB/sec from the host and 4MB/sec frm the client. Is this normal?

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migrated from Apr 20 '10 at 21:12

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I've always wanted to be commenting on a question or answer by someone named Earl so that people had to spell out my full name(instead of ear) :) – Earlz Apr 20 '10 at 21:34

As Scott Hanselman says:

When you're running an OS within and OS and maintaining a FileSystem within a FileSystem, not to mention sharing a hard drive spindle, there's lots of opportunities for things to go very slowly.

If you're interested in improvements (not exactly the whole theory about virtual hard disks) the Scott Hanselman advices are very good.

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Well, look at the speed of the virtual usb port in your guest vm. It may give some clues. For instance, there are various usb ports with varying speeds:1.5M, 12M, 480M.

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