Re: fssconfig/raidframe/dump-related crashes

[Paul Goyette <paul%whooppee.com@localhost>]

On Fri, 11 Mar 2016, Timo Buhrmester wrote:

> My 7-stable/amd64 server crashes nearly every night while my backup
> routine is in progress.  There's no backtrace and no crash dump is saved,
> but the console reads:
> > ohci1: 1 scheduling overruns
> > ohci1: WARNING: addr 0x01cf0000 not found
> > ohci1: WARNING: addr 0x012c0000 not found
> > ohci1: WARNING: addr 0x01cf0000 not found
> > ohci1: WARNING: addr 0x01d50000 not found
> > ohci1: WARNING: addr 0x01d70000 not found
> > ohci1: WARNING: addr 0x01d60000 not found
> > ohci1: WARNING: addr 0x012c0000 not found
> > ohci1: WARNING: addr 0x01cf0000 not found
> > ohci1: 44 scheduling overruns
> > [more of these]
> > ohci1: 46 scheduling overruns
> before it reboots (sometimes hangs instead).
>
> Probably, these messages are /not/ traces of the root cause, since the
> machine will also crash with a kernel with no ohci support compiled in
> whatsoever - the crashes are silent, then.

Perhaps you can get it to provide a backtrace rather than just simply 
rebooting?


> It happens while dump(8)ing an in-filesystem fss(4)-snapshot of an empty-ish
> FFSv1 (fslevel 4) filesystem sitting on a raid(4)-1 with two components.
>
> There should not, conceptually, be a problem with dumping a fss device,
> right?
>
> The command my script runs to create the snapshot is
> # fssconfig -cx fss0 /stor /stor/snapshot
> and the dump
> # dump -$lvl -uant -h 0 -L "$nam" -f - /dev/rfss0 >/tmp/dumpfifo
> where /tmp/dumpfifo is a fifo from which
> # gzip -1 </tmp/dumpfifo >/var/tmp/dump.gz
> reads.  (I don't remember the reason for going via a fifo, but there
> was one...)
>
> Any suggestions where I could start looking?  So far, I've tried running
> a DEBUG kernel but that didn't provide additional information.
> The filesystem is clean as far as fsck_ffs is concerned, too.


I use the built-in snapshot capability of dump(8), with the -X option:

	dump -0au -h 0 -X -f- ${fs} | gzip -9 > $outfile

and it hasn't had any issues.  But I'm not using raid, so that could be 
a factor.


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