order of preference / multipath.conf

order of preference / multipath.conf

[Paul Cote]

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I found this in an old thread and want to confirm as it will influence
how/what we include in multipath.conf

 

Is the following order of preference accurate? 

 
1) Multipaths section (in /etc/multipath.conf)
2) Device section   (in /etc/multipath.conf)
3) Defaults section (in /etc/multipath.conf)
4) Internal default (hwtable.c)
 
If so; then inclusions in the default section; such as setting multibus
as the path grouping policy; would adversely affect any active / passive
array definitions in hwtable.c. 
 
There really should be more guidance concerning these matters. Is this
documented somewhere?
 

Thanks,

Paul


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Re: order of preference / multipath.conf

[Tore Anderson]

* Paul Cote

> Is the following order of preference accurate? 
> 
>  
> 1) Multipaths section (in /etc/multipath.conf)
> 2) Device section   (in /etc/multipath.conf)
> 3) Defaults section (in /etc/multipath.conf)
> 4) Internal default (hwtable.c)

I think maybe that number 3 and 4 is swapped, but don't take my word for
it.  It should be easy to do some tests and figure it out for yourself
by using the "show config" command inside the "multipathd -k" shell with
a few different configuration files.

Regards
-- 
Tore Anderson

Re: order of preference / multipath.conf

[Stefan Bader]

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2007/11/21, Paul Cote <paul.cote@incipient.com>:
>
>
>
> I found this in an old thread and want to confirm as it will influence
> how/what we include in multipath.conf
>
>
>
> Is the following order of preference accurate?
>
>
>
> 1) Multipaths section (in /etc/multipath.conf)
>
> 2) Device section   (in /etc/multipath.conf)
>
> 3) Defaults section (in /etc/multipath.conf)
>
> 4) Internal default (hwtable.c)
>
>
>
> The last two (3 and 4) are the other way round. If there is an entry in
hwtable.c, this will take effect.

Stefan

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RE: order of preference / multipath.conf

[Paul Cote]

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Stefan / Tore

 

Thanks ... and good to know that hwtable.c entries take precedence over
defaults.

 

 

-----Original Message-----
From: dm-devel-bounces@redhat.com [mailto:dm-devel-bounces@redhat.com]
On Behalf Of Stefan Bader
Sent: Wednesday, November 21, 2007 11:48 AM
To: device-mapper development
Subject: Re: [dm-devel] order of preference / multipath.conf

 

 

2007/11/21, Paul Cote <paul.cote@incipient.com>:

 

I found this in an old thread and want to confirm as it will influence
how/what we include in multipath.conf

 

Is the following order of preference accurate? 

 
1) Multipaths section (in /etc/multipath.conf)
2) Device section   (in /etc/multipath.conf)
 
3) Defaults section (in /etc/multipath.conf)
4) Internal default (hwtable.c)
 
 

The last two (3 and 4) are the other way round. If there is an entry in
hwtable.c, this will take effect.

Stefan 


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RE: order of preference / multipath.conf

[Christophe Varoqui]

The hardware table is a "device" array.
This array has no precedence over the array fetched from the config
file.

The logic thus looks like ...

1) Multipaths section (in /etc/multipath.conf)
1bis) N/A
2) Device section   (in /etc/multipath.conf)
2bis) Internal default (hwtable.c) 
3) Defaults section (in /etc/multipath.conf)
3bis) Internal default (config.h)