I can confirm this bug on both of my F16 installations. One were upgraded with preupgrade, the other with yum --releasever=16 upgrade.
In both cases I get huge amounts of IO, it takes yum up to 10min to list packages to be upgraded. And then the next 10min to finish yum after `cleaning' the last package. On one system updated with yum (not preupgrade) the trick with mp_size=1MB did the job (on the other I didn't try yet)
I can confirm this bug on both of my F16 installations. One were upgraded with preupgrade, the other with yum --releasever=16 upgrade.
In both cases I get huge amounts of IO, it takes yum up to 10min to list packages to be upgraded. And then the next 10min to finish yum after `cleaning' the last package. On one system updated with yum (not preupgrade) the trick with mp_size=1MB did the job (on the other I didn't try yet)
**I think it is a high-priority bug**