[dm-devel] [PATCH 3/6] libmultipath: add overrides section to multipath.conf

[Sebastian Herbszt]

Hello Christophe,

Christophe Varoqui wrote:
> Hi,
> 
> the precedence chain is :
> 
> multipaths > user-specified per-device > default per-device > default
> 
> The issue adressed by Ben's patch would not be solved by your suggestion,
> as far as I can see. The proposed override section is just a way not repeat
> a per-device in each multipath (insane) or device (tedious) section.

care to explain why setting the precedence to

multipaths > user-specified per-device > default > default per-device

would not fix the issue?

Lets assume the following default device and user configuration:

.vendor        = "COMPELNT",
.product       = "Compellent Vol",
.pgpolicy      = MULTIBUS,
.pgfailback    = -FAILBACK_IMMEDIATE
.no_path_retry = NO_PATH_RETRY_QUEUE,
.checker_name  = TUR

defaults {
	no_path_retry fail
}

devices {
        device {
                vendor "COMPELNT"
                product "Compellent Vol"
		path_grouping_policy "group_by_prio"
	}
}

multipaths {
	multipath {
		wwid 1234
		failback 15
	}
}

The default section should change no_path_retry from "queue" to "fail".
The device section should change path_grouping_policy from "multibus"
to "group_by_prio" for "COMPELNT/Compellent Vol".
The multipath section should change failback from "immediate" to 15
for wwid 1234.
The path_checker would still be "tur".

Is this not what the "overrides" patch intended?

Sebastian