How to speed up startup?

[Shixin Zeng]

The system startup takes a very long time. In particular, hotplug
takes about 20 seconds to finish on my box, while takes several
seconds on my roommate's.
The hardware are almost the same powerful, on some degree, my hardware
is more powerful than his. So I can't understand why my hoary startup
is much slower than his. The possible significant difference is: My
box, sid(installed 2 years ago)->warty->hoary; and his, warty->hoary.
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Best regards

Shixin Zeng