Re: bio too big device

[Neil Brown]

On Tuesday March 11, [e-mail] wrote:
> I frequently receive this message in my syslog, apparently 
> whenever there are periods of significant write activity:
> 
>     bio too big device ide0(3,7) (256 > 255)
>     bio too big device ide1(22,6) (256 > 255)
> 
> It's worth noting that on this system I have had ongoing trouble 
> with system stability during write activity as well, using a 
> wide variety of 2.5.x kernels, even though at the time of this 
> symptom things are apparently running fine.
> 
> Filesystems are all ext3 on top soft raid0 devices. This happens 
> to be 2.5.64, but it has been happening for at least the last 
> 5-6 versions.
> 
> Ideas? Any further debugging output I can provide?

raid0 doesn't really work well in 2.5 yet.... as you have noticed.

We really need to grab the bio splitting code out of md/dm.c and use
it to split bios that are too big or that cross device boundaries.

any volunteers??

NeilBrown