CentOS - Jan 2017 - multipath show config different in CentOS 7?

Hello,
suppose I want to use a special configuration for my IBM/1814 storage array
luns, then I put something like this in multipath.conf

devices {
        device {
                vendor "IBM"
                product "^1814"
                product_blacklist "Universal Xport"
                path_grouping_policy "group_by_prio"
                path_checker "rdac"
                features "0"
                hardware_handler "1 rdac"
                prio "rdac"
                failback immediate
                rr_weight "uniform"
                no_path_retry "12"
        }
}

In CentOS 6.x when you restart multipathd or restart server, using

multipathd -k
multipathd> show config
multipathd> exit

in output you see your particular configuration instead than the default
one for this particular device.
In CentOS 7.3 instead I see it two times, the first one with the default
built-in values (eg "no_path_retry   fail") and at the end the
customized
one.
So it is not clear what is the actual configuration that device mapper
multipath is using...
The last wins?
Is this expected behaviour? In that case what command can I use to
crosscheck it (apart from real testing that is anyway necessary to verify
too)?
Eg in CentOS 7.3 I'm using device-mapper-multipath-0.4.9-99.el7_3.1.x86_64
while on CentOS 6.8 I'm using device-mapper-multipath-0.4.9-93.el6.x86_64

Thanks in advance,
Gianluca

Am 31.01.2017 um 22:51 schrieb Gianluca Cecchi:
> Hello,
> suppose I want to use a special configuration for my IBM/1814 storage array
> luns, then I put something like this in multipath.conf
>
> devices {
>         device {
>                 vendor "IBM"
>                 product "^1814"
>                 product_blacklist "Universal Xport"
>                 path_grouping_policy "group_by_prio"
>                 path_checker "rdac"
>                 features "0"
>                 hardware_handler "1 rdac"
>                 prio "rdac"
>                 failback immediate
>                 rr_weight "uniform"
>                 no_path_retry "12"
>         }
> }
>
> In CentOS 6.x when you restart multipathd or restart server, using
>
> multipathd -k
> multipathd> show config
> multipathd> exit
That prints out the build-in defaults. See

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/pdf/DM_Multipath/Red_Hat_Enterprise_Linux-7-DM_Multipath-en-US.pdf

chapter 4.
> in output you see your particular configuration instead than the default
> one for this particular device.
> In CentOS 7.3 instead I see it two times, the first one with the default
> built-in values (eg "no_path_retry   fail") and at the end the
customized
> one.
> So it is not clear what is the actual configuration that device mapper
> multipath is using...
> The last wins?
> Is this expected behaviour? In that case what command can I use to
> crosscheck it (apart from real testing that is anyway necessary to verify
> too)?
> Eg in CentOS 7.3 I'm using
device-mapper-multipath-0.4.9-99.el7_3.1.x86_64
> while on CentOS 6.8 I'm using
device-mapper-multipath-0.4.9-93.el6.x86_64
>
> Thanks in advance,
> Gianluca
To configure a custom setup and enable it please see chapter 3 of the 
RHEL documentation about device-mapper multipath.

Regards

Alexander