[dm-devel] Multipath and HSG80 phase 2

[christophe.varoqui at free.fr]

> I can think of at least 1 reasonable reason why you have "long" delays with
> the Emulex driver. It attempts to hide temporary device loss for normal
> operation. Thus, there's a timer that waits before we start erroring i/o. For
> multipathing - you want this timer as low as zero.
>
Indeed, the long delay is due to the tmo value ... leaving the oops though :)
I'd like to set this param from the tools but don't want to special-case every
other hardware.

Do you plan on standardizing the parameter name ? Does Qlogic provides a simalar
 params through sysfs ?

> If you're running the 8.x driver , try setting the module parameter
> lpfc_nodev_tmo=0. Also, older driver revs had issues with "cable pulls",
> which are the port removal tests. In order to get decent behavior, we
> required a kernel patch (in 2.6.10-rc's), a minimum driver rev of 8.0.14 (but
> I'd run the latest anyway - it's 8.0.16), and compilation by "make
> BUILD_FC_TRANS=1" (see the RELEASE-NOTES file).  Sorry this isn't plug-n-play
> yet. It will be as we complete the upstream process.
>
Yes I already use 8.0.16
I sent the oops in a separate email if you want to diagnose if lpfc is the
culprit ...

regards,
cvaroqui