Re: Sun StorageTek 2530 and dm?

From: Chandra Seetharaman <sekharan@us.ibm.com>
To: device-mapper development <dm-devel@redhat.com>
Subject: Re: Sun StorageTek 2530 and dm?
Date: Mon, 24 Aug 2009 16:11:35 -0700	[thread overview]
Message-ID: <1251155495.24406.62.camel@chandra-ubuntu> (raw)
In-Reply-To: <Pine.LNX.4.64.0908241852270.21130@e-smith.charlieb.ott.istop.com>

On Mon, 2009-08-24 at 18:58 -0400, Charlie Brady wrote:
> On Mon, 24 Aug 2009, Jakov Sosic wrote:
> 
> > On Mon, 24 Aug 2009 13:44:34 -0700
> > Chandra Seetharaman <sekharan@us.ibm.com> wrote:
> >
> >> ok.. simple words; That patch won't help you.
> >
> > hm :( so defining "SUN" "LCMS100_S" won't help? Although in
> > scsi_dh_rdac only "SUN" "LCMS100_F" is defined. And that stands for
> > Fiber, while mine is SAS cabling...
> 
> Chandra says that the patch won't help you. Perhaps he can clarify. My 
> understanding is that if you configure multipath to use RDAC that the 
> driver does have to be patched so that the RDAC handler will be used. I 
> did find that to be the case with the StorageTek 2510 "LCMS100_I").

I didn't mean that scsi_dh_rdac module won't help him. It would.

His device is being handled by the scsi_dh_rdac module once he added the
stanza to /etc/multipath.conf file.

But, the problem he is seeing is different and adding this device to the
devlist in scsi_dh_rdac wouldn't solve his problem.

Hope it is clear now.

> 
> My understanding also is that RDAC is superior, so RDAC hander support is 
> desirable.
> 
> > I've recompiled RPM with added patch, then extracted single module
> > (scsi_dh_rdac.ko), and put it in place of the original module...
> >
> > FATAL: Error inserting scsi_dh_rdac
> > (/lib/modules/2.6.18-128.4.1.el5xen/kernel/drivers/scsi/device_handler/scsi_dh_rdac.ko):
> > Invalid module format
> >
> > I guess I'll have to build the whole kernel just because of this :(
> 
> No, it is certainly possible to build an RPM which contains just the 
> module that you need. But you do need to build correctly.
> 
> I did make the suggestion earlier that it would be useful if the module 
> could take load-time parameters to add support for additional devices. I 
> think it was Chandra who agreed that was a good idea and he would add it 
> to the TODO list, but neither he nor I has done that yet.
> 
> >> This is uncalled for!!
> >
> > Sorry, I'm easily flammable...
> 
> You would be wise to control your urges, if you wish people to help you.
> 
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