[CentOS] DRBD on a xen host: crash on high I/O

Wed Jul 29 13:55:01 UTC 2009
Ross Walker <rswwalker at gmail.com>

On Jul 29, 2009, at 7:52 AM, "Andrea Dell'Amico"  
<adellam at sevenseas.org> wrote:

> On Tue, 2009-07-28 at 14:31 -0400, William L. Maltby wrote:
>>> When the two hosts are in sync, if I activate more than a few (six  
>>> or
>>> seven) xen guests, the master server crashes spectacularly and  
>>> reboots.
>>> I've seen a kernel dump over the serial console, but the machine
>>> restarts immediately so I didn't write it down.
>> If you have an available pc, hook it up in place of the serial  
>> console
>> and start a terminal emulator, e.g. minicom or whatever you prefer,  
>> and
>> turn on full logging. This should save everyting in a file that you  
>> can
>> then review.
> Uhm. The console is on the DRAC5 card. I think I would need to  
> activate
> some network kernel crash dump feature.
>> If it's a Windows based, just remember to get rid of the ^M with
>> dos2unix, or equivalent, after you send it to a *IX box.
>> I don't know anything about the rest of your problem, sorry.
> As I wrote, it's a production server. I cannot stop it when I want, I
> need to reserve a weekend session.
> In the meantime, I was asking if there's a known problem with a setup
> like mine.

I read on another forum how a user using iSCSI for domUs was  
experiencing network hangs due to the fact that dom0 didn't have  
enough scheduler credits to handle the network throughput. That might  
be related.