multipathing Sun 6140

multipathing Sun 6140

[Gustavo Riveros]

Hi dm-developers,

I'm having problem with multipathing device-mapper with my linux server, 
but this was resolved by Thread "multipathing flip flopping on Sun 6140" 
very well 
(http://www.redhat.com/archives/dm-devel/2007-August/msg00066.html)

The configuration is the same:

X4600 Server
2 HBA's Emulex
SAN STK6140

but in dmesg i have the following error message:

Buffer I/0 error on device sdf, logical block 0
end_request: I/0 error, dev sdf, sector 0

Did you know the error message?

Thanks,
Gustavo Riveros

Re: multipathing Sun 6140

[Konrad Rzeszutek]

On Wed, Jun 04, 2008 at 05:14:57PM -0400, Gustavo Riveros wrote:
> Hi dm-developers,
>
> I'm having problem with multipathing device-mapper with my linux server, 
> but this was resolved by Thread "multipathing flip flopping on Sun 6140" 
> very well 
> (http://www.redhat.com/archives/dm-devel/2007-August/msg00066.html)

That multipath.conf entry seems to be missing some key elements:

     device {
                vendor                  "SUN"
                product                 "CSM200_R"
                product_blacklist       "Universal Xport"
                features                "1 queue_if_no_path"
                path_checker    rdac
                hardware_handler        "1 rdac"
                path_grouping_policy    group_by_prio
                prio                    "rdac"
                failback                immediate
        }

>
> The configuration is the same:
>
> X4600 Server
> 2 HBA's Emulex
> SAN STK6140
>
> but in dmesg i have the following error message:
>
> Buffer I/0 error on device sdf, logical block 0
> end_request: I/0 error, dev sdf, sector 0
>
> Did you know the error message?

That would imply you are using the 'readsector0' checker program
instead of the 'rdac' one.

The multipath.conf above assumes that this controller is indeed an RDAC
one. I don't have one so the configuration might be completly wrong.

Re: multipathing Sun 6140

[Chandra Seetharaman]

On Wed, 2008-06-04 at 17:14 -0400, Gustavo Riveros wrote:
> Hi dm-developers,
> 
> I'm having problem with multipathing device-mapper with my linux server, 
> but this was resolved by Thread "multipathing flip flopping on Sun 6140" 
> very well 
> (http://www.redhat.com/archives/dm-devel/2007-August/msg00066.html)
> 
> The configuration is the same:
> 
> X4600 Server
> 2 HBA's Emulex
> SAN STK6140
> 
> but in dmesg i have the following error message:
> 
> Buffer I/0 error on device sdf, logical block 0
> end_request: I/0 error, dev sdf, sector 0
> 
> Did you know the error message?

This is the error message that is printed when the lun is accesses thru
the passive paths. These are _not_ a problem.

They will not appear if all the access to the luns are thru the dm
devices (in which case you will see these only during device probing
time.

I am pushing a set of patches (currently in -mm, and hopefully will get
into 2.6.27) that will get rid of these messages.

> 
> Thanks,
> Gustavo Riveros
> 
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