Re: preupgrade: Generating metadata hang

Seth Vidal wrote:
>
>
> 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
>
I don't know what it's doing. It just shows the progress bar overlayed 
with "Generating metadata XX%" and at some point before it finishes it 
locks up.

Regards,
Gerry