Re: preupgrade: Generating metadata hang

On Wed, 25 Mar 2009, Gerry Reno wrote:

> We're seeing a number of hangs using preupgrade at the "Generating metadata 
> ..." stage.  The hangs are so tight that they corrupt the mdraid arrays which 
> were probably in the middle of a write.  The causes the arrays to resync on 
> next boot which takes a couple hours.  The hang always occurs on a disk 
> access as we can see the array activity light stays on after the hang.  I 
> suspect some type of uninterrupible infinite loop is going on.  Once the hang 
> occurs the server completely stop responding to inputs: network, keyboard, 
> mouse, etc.  I did not find any core files upon reboot.
>
> We're on our fourth attempt with one machine to get preupgrade to complete 
> without this hang.

Is it in the middle of making the sqlite files? That's the only thing I 
can think of that's very disk-write intensive.

-sv