Re: EMC Powerpath and ASMLib

From: Jeremy Schneider <>
Date: Wed, 04 Mar 2009 19:52:16 -0600
Message-ID: <>

We did spend a lot of time on this decision. (We will potentially deploy up to a few hundred clusters based on our design.) We decided to avoid Powerpath and use Linux built-in multipathing (devmap-based) on RH5. I think that ASMLIB is fine with devmap-mpath; we chose not to use it but I think that there are some trade-offs both ways... most people probably will use it.

There are some good arguments for devmap and I think I remember a fairly recent endorsement of it on the ocfs2 list; I also wrote up some speculation about reasons against it on a blog post not too long ago over at


Raj Mareddi wrote:
> Fellow DBAs,
> We gotta make a decision to use raw devices of powerpath or ASMLib
> over powerpath. I know ASMLib historically got some issues with
> Powerpath(cause ASM Couldn't understand mutlipathing). But it sounds
> like these issues are now fixed with Linux kernel 2.6 and 2.0 ASMLib.
> However, The EMC white paper for best practices doesn't mention ASMLib
> at all.
> Just curious on what you guys using ? or What option would you use and
> why ?
> (I personally prefer raw device names of power path (by using pseudo
> names), just as explained in
> I am sure lot of you are already through this situation. Would you
> please share your thoughts and experience ?
> Thanks,
> Raj Mareddi

Jeremy Schneider
Chicago, IL

Received on Wed Mar 04 2009 - 19:52:16 CST

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