Comment 6 for bug 582264

Same happens to me.

When there is intense disk activity (copying files, installing packages, etc ...) the whole system becomes extremely slow and unresponsive. This is quite annoying as it renders the system unusable while copying files or doing an apt-get upgrade. This definitely did not happen in Karmic.

I have tested a mainline kernel build (linux-image-2.6.32-0206321405-generic_2.6.32-0206321405_amd64.deb) and the one from the Maverick liveCD, as suggested above. In both cases things went smooth, without stalls. I started to copy a large directory, and simultaneously I could open firefox and navigate without any noticeable lag. The problem seems to be in the ubuntu lucid kernel then ...