Buffer I/O error on device nbd0

Buffer I/O error on device nbd0

[Peter]

Hi.  We get the errors below in the kernel logs.

WARNING: Kernel Errors Present
Buffer I/O error on device nbd0, ...: 27 Time(s)
Buffer I/O error on device nbd16,...: 3 Time(s)
end_request: I/O error, dev nbd0, secto...: 13 Time(s)
end_request: I/O error, dev nbd1, secto...: 7 Time(s)
end_request: I/O error, dev nbd10, sect...: 7 Time(s)

I see someone else has reported this error message.  E.g. see:
http://lists.xensource.com/archives/html/xen-devel/2004-09/msg00348.html

I'm not sure what we are running in /etc/init.d that could be starting 
something that triggers this error.  And I don't believe we see the same 
error when we use the same file system under UML (but that may be 
because we have different kernel options enabled).

Has there been any further thought as to what triggers these error 
messages?  Or do you have any advice on what we can do to try and avoid 
them?

Regards, Peter
http://rimuhosting.com - Xen VPS Hosting

Re: Buffer I/O error on device nbd0

[Keir Fraser]

On 6 Aug 2005, at 11:53, Peter wrote:

> I'm not sure what we are running in /etc/init.d that could be starting 
> something that triggers this error.  And I don't believe we see the 
> same error when we use the same file system under UML (but that may be 
> because we have different kernel options enabled).
>
> Has there been any further thought as to what triggers these error 
> messages?  Or do you have any advice on what we can do to try and 
> avoid them?

I think they appear during udev or lvm startup. It may be because we 
build NBD as part of domU configuration (although only as a module). If 
this is only happening on domU then it's worth trying to remove NBD 
support from kernel configuration and recompile.

  -- Keir