Re: hanging tapdisk2 processes and improper udev rules

["Sébastien RICCIO" <sr@swisscenter.com>]

> The processes, really? Where do they hang? (check out the wait state --
> ps -eopid,wchan:25,cmd or so).
>
> Or do you mean they're stuck waiting for I/Os?
>
> Daniel
>
>

They seems to work and to do their job, but they are in a strange state. 
For example a ps -aux on dom0 hangs when processing
the line about the tapdisk process, also it cannot be detached from the 
vm, and issuing a reboot of the host hangs too (can't kill the process 
so it doesn't reboot).

I fighted quite a lot with this on a debian6 + xen 4.1.x  box and found 
out that disabling the  multipath-tools and multipath-tools-boot 
corrected the problem (but I need them). I thought that maybe it was 
beacause multipathd try to "multipath" the block device
handled by blktap2 and somehow locks it. But it's speculations :)

I do not have the the hands on the box at the moment to give you more 
informations and do not want to hijack this thread. It's just that it 
looked like the problem I encountered, but I will send you more 
informations when I am on the box.

Thanks,
Sébastien