[dm-devel] Re: [multipath] SCSI device capacity mess

[christophe varoqui]

Le mardi 26 octobre 2004 à 17:34 -0400, James Bottomley a écrit :
> On Tue, 2004-10-26 at 19:27, christophe varoqui wrote:
> > 1) make the /sys/block/*/size attribute writable
> > 2) resurrect a BLKSETSIZE ioctl
> > 3) make device-mapper less strict, and hope we can fix the size by a
> > device rescan when it get activated
> > 4) sell the culprit hardware
> 
> Only 3 & 4 look viable.  There's little point introducing an extra API
> or ioctl specifically to defeat a check, since the check will now be
> useless anyway.
> 
:) I feared you would vote for 4)
That is not that viable for me, as you can imagine.

The culprit hardware, should I have reported, is a HSG80 controler pair
configured in multibus mode.

I though you could have considered 1) as it is just another way for root
to shoot itself and the multipath daemon can apply to detected valid
size on other paths to apply it to ghost paths. That didn't seem so
awkward to me.

I fear Alasdair reaction to 3) will be cold ... I still hope we can come
out with a solution, even one I havn't thought about.

> The "random" value is 1GB by the way.  Since the dawn of time SCSI has
> reported this for devices that failed read capacity.
> 
Ah, good to know. Thanks

regards,
-- 
christophe varoqui <christophe.varoqui at free.fr>