Re: [RFC] Multi-path IO in 2.5/2.6 ?

From: Heinz J . Mauelshagen (Heinz.Mauelshagen@t-online.de)
Date: Tue Sep 10 2002 - 05:30:47 EST


On Mon, Sep 09, 2002 at 12:49:44PM +0200, Lars Marowsky-Bree wrote:
> Morning everyone,
>
> I hope people are waking up by now ;-)
>
> So, what is the take on "multi-path IO" (in particular, storage) in 2.5/2.6?
>
> Right now, we have md multipathing in 2.4 (+ an enhancement to that one by
> Jens Axboe and myself, which however was ignored on l-k ;-), an enhancement to
> LVM1 and various hardware-specific and thus obviously wrong approaches.
>
> I am looking at what to do for 2.5. I have considered porting the small
> changes from 2.4 to md 2.5. The LVM1 changes are probably and out gone, as
> LVM1 doesn't work still.
>
> I noticed that EVMS duplicates the entire md layer internally (great way to
> code, really!), so that might also require changing if I update the md code.
>
> Or can the LVM2 device-mapper be used to do that more cleanly?

We have a multi-path target for device-mapper planned for later this year.

This will be a multi-path addon to the generic mapping service(s)
device-mapper already provides which can multi-path access to any
arbitrary given block device, not just logical volumes.

>
> I wonder whether anyone has given this some thought already.

We did ;)

>
>
> Sincerely,
> Lars Marowsky-Brée <lmb@suse.de>
>
> --
> Immortality is an adequate definition of high availability for me.
> --- Gregory F. Pfister
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/

-- 

Regards, Heinz -- The LVM Guy --

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen Sistina Software Inc. Senior Consultant/Developer Am Sonnenhang 11 56242 Marienrachdorf Germany Mauelshagen@Sistina.com +49 2626 141200 FAX 924446 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Sun Sep 15 2002 - 22:00:20 EST