From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: /sys/.../enclosure_device: ? Date: Wed, 13 Jan 2016 12:30:07 -0800 Message-ID: <1452717007.2363.22.camel@HansenPartnership.com> References: <2054826122.7150196.1452702532315.JavaMail.zimbra@redhat.com> <1452712505.2363.19.camel@HansenPartnership.com> <1033193682.7255311.1452716104867.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:44970 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752616AbcAMUaJ (ORCPT ); Wed, 13 Jan 2016 15:30:09 -0500 In-Reply-To: <1033193682.7255311.1452716104867.JavaMail.zimbra@redhat.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Anne Mulhern Cc: linux-scsi@vger.kernel.org On Wed, 2016-01-13 at 15:15 -0500, Anne Mulhern wrote: > > > > ----- Original Message ----- > > From: "James Bottomley" > > To: "Anne Mulhern" , > > linux-scsi@vger.kernel.org > > Sent: Wednesday, January 13, 2016 2:15:05 PM > > Subject: Re: /sys/.../enclosure_device: ? > > > > On Wed, 2016-01-13 at 11:28 -0500, Anne Mulhern wrote: > > > Hi! > > > > > > I'm looking for the most precise information available about the > > > meaning of > > > and from what it is derived. I'm also interested in what the > > > values > > > in the files in that directory > > > may mean. Could somebody point me there? > > > > It's in drivers/misc/enclosure.c:enclosure_link_name() > > > > Thanks. I will do my best with that. > > > > Also, how can there be more than one enclosure_device > > > subdirectory > > > for the same device, > > > or, alternatively, why isn't stored in a file in the > > > more > > > regularly named directory > > > /sys/.../enclosure_device? > > > > I'm not sure I parse the question, but if you're asking how can a > > single enclosure bay appear to have more than one device, that's > > when > > there are multiple paths to the device. > > I'm afraid the word path is so overloaded...I'm assuming that you > are talking about a multipathed environment, where two device nodes, > say /dev/sdb, /dev/sdc correspond to the same disk, and are hence > multipathed. Of course, in that case, it makes sense that both > devices should share a bay. And that's what I observe. Yes, that's what I meant. > If I understand you correctly, then my question is actually the > opposite. Why does it look as if the directories are set up so that > there can be multiple bays for a single device...i.e., the directory > naming scheme allows me to specify an arbitrary number of bays for > /dev/sdb. It seems like there should never be more than one? There is only one bay per device since a physical disk can't be in more than one bay at once. Why do you think it was set up to allow >1? James > - mulhern > > > James > > > > > (It would be nice to be able to obtain the value of > > > using > > > libudev's attribute > > > lookup facilities, but making that value a part of the specially > > > named directory enclosure_device: > > > makes such a process especially difficult.) > > > > > > Thanks, > > > > > > - mulhern > > > -- > > > To unsubscribe from this list: send the line "unsubscribe linux > > > -scsi" > > > in > > > the body of a message to majordomo@vger.kernel.org > > > More majordomo info at > > > http://vger.kernel.org/majordomo-info.html > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux > > -scsi" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" > in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >