From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Date: Fri, 30 Mar 2012 08:23:46 +0000 Subject: Re: Missing SAS phy enumeration in newer versions of udev path_id Message-Id: <4F756D92.1090206@suse.de> List-Id: References: <4F7567F1.2010201@ericsson.com> In-Reply-To: <4F7567F1.2010201@ericsson.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable To: linux-hotplug@vger.kernel.org On 03/30/2012 09:59 AM, Nils Carlson wrote: > Hi, >=20 > We recently upgraded our version of udev and I saw that the symlinks > under /dev/disk/by-path/ have changed since udev started using the > path_id C code to no longer include phy enumeration for SAS disks. > Was this change intentional? Would anyone mind if i re-create the > behavior of the old bash script as we were using it? >=20 Not everybody at once ... I've just had several customer calls for exactly the same issue. Actually ... the company name seems to be vaguely familiar ... To quote myself: > Problem is that SAS has something called 'wide-ports', ie inherent > port-bonding for SAS. When a system has wide ports, several PHYs > are merged _physically_ together into a single connector. > However, on the system side we're only seeing PHYs, so it' > impossible to tell which of the phy has been used. > > So to handle this correctly we would need to generate symlinks for > each phy in a wide port; however, currently the path_id program is > only capable of printing out _one_ link per wide port. > > And actually, the original path_id script also printed out only > one symlink, so even there it didn't handle wide ports correctly. > I've discussed this issue with Kay Sievers, and we agreed that we should be fixing this. It should be relatively easy to update the path_id program to print out a link for each phy in a wide-port, and then we could do a static enumeration via udev rules like $env{ID_SAS_PHY0}=3D"?*", SYMLINK+=3D"/dev/disk/by-path/$ID_SAS_PHY0" $env{ID_SAS_PHY1}=3D"?*", SYMLINK+=3D"/dev/disk/by-path/$ID_SAS_PHY1" seeing that there is currently a max of 8 phys per wide port, we only would need to specify 8 lines here. Which should be too bad. You're welcome to lend a hand ... Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg)