Re: [dm-devel] info on enabling only one path with rdac and DS4700

[Christophe Varoqui <christophe varoqui gmail com>]

> I'm on a IBM HS21 blade connected to a DS4700 storage array.
> Without doing nothing in multipath.conf but blacklisting the internal
> disk, I get this kind of configuration:
> # multipath -l
> mpath1 (3600a0b80005012440000093e4a55cf33) dm-6 IBM,1814      FAStT
> [size=3.4T][features=1 queue_if_no_path][hwhandler=1 rdac][rw]
> \_ round-robin 0 [prio=0][active]
>  \_ 3:0:0:1 sdb 8:16  [active][undef]
>  \_ 4:0:0:1 sdc 8:32  [active][undef]
> \_ round-robin 0 [prio=0][enabled]
>  \_ 3:0:1:1 sdd 8:48  [active][undef]
>  \_ 4:0:1:1 sde 8:64  [active][undef]
> 
> Is there any config option I can force to use only one path at a time
> in the active controller, instead of two (sdb and sdc in my case) in
> round robin as I see in iostat?
> 
What ever the reason you'd want to do that, setting the path group
policy to failover would create 4 1-path groups. I'd have 1 active paths
and 3 spares.

Regards,
-- 
Christophe Varoqui
OpenSVC - Tools to scale
http://www.opensvc.com/