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

[Lars Marowsky-Bree <lmb@suse.de>]

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?

I wonder whether anyone has given this some thought already.


Sincerely,
    Lars Marowsky-Brée <lmb@suse.de>

-- 
Immortality is an adequate definition of high availability for me.
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