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Re: [rhelv5-list] Getting many paths attached to each lun

> In redhat5.2 , I have 3 luns (symmetrix)  attached to the server.
> Just after installation  when I checked
> with 'fdisk -l ' command , found  each  luns are attached to 9 paths.

I'd be curious how you have your san and lun configured, both hardware and
software.  Atleast in a basic sense.  I'll explain why in a moment.

> I dont have any concepts still yet  about  multipath, though
> multipath rpm is being installed but the
> daemon is not started.

I would recommend reading up on multipath, i've included some links below.

> Later ,  I installed EMC powerpath and also found  each lun is
> attached to 9 luns.

In my experience, unless you have a good reason to use PowerPath over the
distribution tools, I wouldn't.  Not to say that there aren't good reasons.
This is a good read:
 and has some links to some other good multipath and storage info

> My qs is why i am seeing  9 paths attched to each lun?  I need two
> paths  attach to each lun.

Like I said earlier, 9 paths is an interesting number.  In every non-failed
scenario I've experienced its always been an even number, but this can
depend heavily on how your system is attached to the SAN.  Effectively you
are supposed to get a device per path to that LUN.  For example, if I have
a SAN with 4 paths to two switches and each switch has 2 paths to my
server.  If I configure the switch to give each path on each side access to
the other (in other words SAN A0 would be one path to the switch, but then
could go over both paths from switch to the server), then I should end up
with 8 paths.

> Any advice/suggession is really appreciated.

As good of a starting place as I can find would be here:


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