[dm-devel] dm-rdac not working?

[Chandra Seetharaman]

On Tue, 2007-08-28 at 08:28 +0200, Tore Anderson wrote:
> * Chandra Seetharaman
> 
> > In RDAC mode, tur will always fail on the passive path. You do not see
> > that ?
> 
>    No, TUR works completely fine on the passive paths.  Only thing that
>   distinguishes a passive path from an active one is that all actual I/O
>   fails.  All "meta"-I/O, like TEST UNIT READY, INQUIRY, READ CAPACITY,
>   and so on, works fine.
> 
It used to fail for me with error. I do not see it with the updated
firmware.

Do you see multiple failures like shown below during the device probe
time ?
--------------------
Aug 28 11:07:25 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:26 lab1 kernel: end_request: I/O error, dev sdd, sector 160
Aug 28 11:07:26 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:26 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:26 lab1 kernel: printk: 41 messages suppressed.
Aug 28 11:07:26 lab1 kernel: Buffer I/O error on device sdd, logical
block 0
Aug 28 11:07:27 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:27 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:28 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:28 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:29 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:29 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:30 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:31 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:31 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:31 lab1 kernel: printk: 8 messages suppressed.
Aug 28 11:07:31 lab1 kernel: Buffer I/O error on device sdd, logical
block 0
Aug 28 11:07:32 lab1 kernel: end_request: I/O error, dev sdd, sector 0
Aug 28 11:07:32 lab1 kernel: end_request: I/O error, dev sdd, sector 0
----------------------
> > You mean mpath_prio_tpc from 0.4.7 ? I use it all the time in both RDAC
> > and AVT mode with no issues.
> 
>    It works fine, it just prints an error message to stderr "Auto-volume
>   Transfer not enabled", which kind of messed up the output from
>   multipath -ll.  So there's just cosmetic reasons for using
>   mpath_prio_rdac over mpath_prio_tpc.
> 
>    root at atalanta:~# /sbin/mpath_prio_tpc /dev/sdg
>    Auto-volume Transfer not enabled6
>    root at atalanta:~# /usr/local/sbin/mpath_prio_rdac /dev/sdg
>    3
> 
Hmm. In my storage it is enabled. That is why I do not see that issue.
May be multipath tools should read and ignore the stderr. 

> > oops :)... attached
> 
>    Since my problem is fixed by the patch pointed to by Brian De Wolf I
>   assume you're no longer interested in this debug.  Tell me if you are.
> 
No, not needed.

>    Thanks for your help!
> 
> Regards
-- 

----------------------------------------------------------------------
    Chandra Seetharaman               | Be careful what you choose....
              - sekharan at us.ibm.com   |      .......you may get it.
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