[CentOS] multipath

nate centos at linuxpowered.net
Tue Jan 12 19:19:15 UTC 2010

Paras pradhan wrote:
> Can anybody tell me if my multipath o/p is fine?

Hitachi support should be able to

> I have a active/active setup and when I unplug the FC SAN cable on one of
> the ports of my HBA my host is being un responsive and need to reboot it.

Sounds like it is mis configured, doing some searches I found several
references to the "/sbin/pp_hds_modular" command, which you may need,
in this situation it's best to deal with your vendor support they
should have instructions for supported MPIO configurations(whether or
not linux device mapper is supported I don't know).

Also double/triple check that your array is truely active-active, from
what I recall you had a really old HDS system, I don't recall many of
them being active-active(in the sense that you can access the same
volume over multiple controllers simultaneously vs having different
volumes exported over different controllers).

For modular active-active I was in a presentation last year by HDS
for their new AMS2k line up and they claimed that was the first
modular active-active array(at least from them), others have had
modular active-active for a few years now, they tried to claim they
were the first despite that not being true.


For me if I yank a cable within a couple seconds the system
recovers, my vendor provides extremely specific step-by-step
instructions for configuring, including modifications to the
multipath init script for proper operation(7 pages in a PDF just
for MPIO configuration and examples).


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