How to accelerate installation of upgrades?

[hhb]

I spend less than half an hour to install an ubuntu 11.10 Alpha 2 in VirtualBox. Then install all upgrades from official source takes me 3 hours(download time not included). It seems that the disk performance is the bottleneck. CPU usage is constantly low. Is there any way to accelerate installation progress?
Thanks.

[dino99]

why not a real install:

http://ubuntuforums.org/showpost.php?p=10161428&postcount=2

[2F4U]

What kind of internet connection do you have? Is it usually slow or just in VirtualBox?

[hhb]

Originally I use a real installation. But recently I change to a new computer Asus U31KI241SD, which seems not well supported by Ubuntu or Fedora.
1. No Optimus support. I'm not really need a independent video adapter, but it consume extra energy.
2. Can not sleep. If I do this, the system just blocked.
3. Brightness of display is wired. From time to time the brightness change to maximum automatically. If I adjust brightness in Gnome3 Setting, the screen flashes(quickly switch between current brightness and maximum brightness).
And many other detailed problem.
These problems happened in Ubuntu or Fedora or even both. I know there are some solutions in the forum. I tried some. Part of them succeed, others don't work. Whatever at last I can not make it really usable.. So I gave up and fallback to Windows, and tried to install a Linux in VirtualBox...

[hhb]

What kind of internet connection do you have? Is it usually slow or just in VirtualBox?
There is nothing related to Internet connection. I use a local mirror in my school, which is extremely fast. The download finished quickly. What make it very slow is the installation. i.e unpacking and something..
During the installation, my CPU usage is very low, but hard disk keeps busy. So I think this may related to disk performance.

[2F4U]

How much RAM is dedicated to the VM?

[hhb]

How much RAM is dedicated to the VM?

1.5 of 4G RAM
2 of 4 cores of i5 2410
15G disk space(13G in /, 2G in swap)