Re: [ceph-users] rbd-nbd crashes Error: failed to read nbd request header: (33) Numerical argument out of domain - Dev

19 May 2021

On Wed, May 19, 2021 at 11:32:04AM +0800, Zhi Zhang wrote:
...
  On Wed, May 19, 2021 at 11:19 AM Zhi Zhang
&lt;zhang.david2011(a)gmail.com&gt;
 wrote:

 On Tue, May 18, 2021 at 10:58 PM Mykola Golub &lt;to.my.trociny(a)gmail.com&gt;
 wrote:

 Could you please provide the full rbd-nbd log? If it is too large for
 the attachment then may be via some public url? 
  ceph.rbd-client.log.bz2

<https://drive.google.com/file/d/1TuiGOrVAgKIJ3BUmiokG0cU12fnlQ3GR/view?usp=drive_web>

 I uploaded it to google driver. Pls check it out.  
 We found the reader_entry thread got zero byte when trying to read the nbd
 request header, then rbd-nbd exited and closed the socket. But we haven't
 figured out why read zero byte? 
Ok. I was hoping to find some hint in the log, why the read from the
kernel could return without data, but I don't see it.

From experience it could happen when the rbd-nbd got stack or was too
slow so the kernel failed after timeout, but it looked different in
the logs AFAIR. Anyway you can try increasing the timeout using
rbd-nbd --timeout (--io-timeout in newer versions) option. The default
is 30 sec.

If it does not help, probably you will find a clue increasing the
kernel debug level for nbd (it seems it is possible to do).

-- 
Mykola Golub