Re: btrfs for files > 10GB = random spontaneous CRC failure.

[Chris Mason <chris.mason@fusionio.com>]

On Tue, Feb 05, 2013 at 03:16:34AM -0700, Tomasz Kusmierz wrote:
> On 16/01/13 09:21, Bernd Schubert wrote:
> > On 01/16/2013 12:32 AM, Tom Kusmierz wrote:
> >
> >> p.s. bizzare that when I "fill" ext4 partition with test data everything
> >> check's up OK (crc over all files), but with Chris tool it gets
> >> corrupted - for both Adaptec crappy pcie controller and for mother board
> >> built in one. Also since courses of history proven that my testing
> >> facilities are crap - any suggestion's on how can I test ram, cpu &
> >> controller would be appreciated.
> >
> > Similar issues had been the reason we wrote ql-fstest at q-leap. Maybe 
> > you could try that? You can easily see the pattern of the corruption 
> > with that. But maybe Chris' stress.sh also provides it.
> > Anyway, I yesterday added support to specify min and max file size, as 
> > it before only used 1MiB to 1GiB sizes... It's a bit cryptic with 
> > bits, though, I will improve that later.
> > https://bitbucket.org/aakef/ql-fstest/downloads
> >
> >
> > Cheers,
> > Bernd
> >
> >
> > PS: But see my other thread, using ql-fstest I yesterday entirely 
> > broke a btrfs test file system resulting in kernel panics.
> 
> Hi,
> 
> Its been a while, but I think I should provide a "definite anwser" or 
> simply what was the cause of whole problem:
> 
> It was a printer!
> 
> Long story short, I was going nuts trying to diagnose which bit of my 
> server is going bad and effectively I was down to blaming a interface 
> card that connects hotswapable disks to mobo / pcie controllers. When 
> I've got back from my holiday I've sat in front of server and decided to 
> go with ql-fstest which in a very nice way reports errors with a very 
> low lag (~2 minutes) after they occurred. At this point my printer 
> kicked in with "self clean" and error just showed up after ~ two minutes 
> - so I've restarted printer and while it was going through it's own post 
> with self clean another error showed up. Issue here turned out to be 
> that I was using one of those fantastic pci 4 port ethernet cards and 
> printer was directly to it - after moving it and everything else to 
> switch all problem and issues have went away. AT the moment I'm running 
> server for 2 weeks without any corruptions, any random kernel btrfs 
> crashes etc.

Wow, I've never heard that one before.  You might want to try a
different 4 port card and/or report it to the driver maintainer.  That
shouldn't happen ;)

ql-fstest looks neat, I'll check it out (thanks Bernd).
 
-chris