<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Hej,<div><br></div><div>The kernel driver in /sys provide little useful information with current releases.</div><div><br></div><div>Even if the nvme driver is extended in future kernels as proposed by Keith Busch this will not solve </div><div>the problem with kernels used today.</div><div><br></div><div>NVMe drives are being deployed now (in mass) and it will only increase rapidly due to the supreme performance.</div><div><br></div><div>I think the most important issue is to define a naming scheme in /dev/disk/by-id to ensure consistent </div><div>naming and how to resolve this naming is secondary.</div><div><br></div><div>If the kernel can provide the more useful information in 4.2 it is great but we need a scheme that is possible </div><div>to create with currently deployed kernels including 2.6.* kernels.</div><div><br></div><div>The scsi_id on arch 4.0.1-1 returns a ID_SERIAL of:</div><div>ID_SERIAL=SNVMe_INTEL_SSDPEDMD40CVFT504600EE400BGN</div><div>or </div><div><div>ID_VENDOR=NVMe</div></div><div><div>ID_MODEL=INTEL_SSDPEDMD40</div></div><div>ID_SCSI_SERIAL=CVFT504600EE400BGN</div><div><br></div><div>on the same kind of system with SuSE 12 (3.12.28) system what you would get (different unit and serial):</div><div><br></div><div>ID_SERIAL=365cd2e4080864356494e000000010000</div><div>or</div><div><div>ID_VENDOR=NVMe</div></div><div><div>ID_MODEL=INTEL_SSDPEDMD40</div></div><div>ID_SCSI_SERIAL=CVFT4324006Z400BGN</div><div><br></div><div><div>A possible scheme to achieve with both is (assuming scsi_id being used):</div><div><br></div><div>/dev/disk/by-id/nvme-$ENV{ID_MODEL}_$ENV{ID_SCSI_SERIAL}</div><div><br></div><div>Distributions could then add necessary patches to achieve the same result as long as we know what </div><div>we want to achieve.</div><div>If additional support is added in future kernel releases, systemd/udev can move away from use of scsi_id.</div><div><br></div><div>BR</div><div>Per</div><div><br></div><div><div>On 14 May 2015, at 19:07 , Keith Busch <<a href="mailto:keith.busch@intel.com">keith.busch@intel.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Kay Sievers <kay <at> <a href="http://vrfy.org">vrfy.org</a>> writes:<br><blockquote type="cite">On Thu, May 14, 2015 at 6:12 PM, Lennart Poettering<br><lennart <at> <a href="http://poettering.net">poettering.net</a>> wrote:<br><blockquote type="cite">Well, nothing changed really: we'd like to remove scsi_id from<br>systemd/udev upstream. Please ask sg_utils to pick it up<br>instead. We'll continue to support the status quo for a while longer,<br>but it can't stay this way, and we shouldn't add new features to<br>it while it's in limbo.<br></blockquote><br>Yeah, not sure how much NVMe has to do with SCSI. It might make more<br>sense to export the primary values to identify these devices by the<br>kernel driver in /sys, instead of excapsulating/emulating the SCSI<br>behavior. The kernel does that for other block device types like mmc<br>too.<br></blockquote><br>I also like native nvme identification over scsi translation. Is the mmc<br>way your preferred method for consuming these? If so, can you provide a<br>pointer in that driver for what they're doing? I can probably get it in<br>the nvme driver for 4.2.<br><br>Thanks,<br>Keith<br><br>_______________________________________________<br>systemd-devel mailing list<br><a href="mailto:systemd-devel@lists.freedesktop.org">systemd-devel@lists.freedesktop.org</a><br>http://lists.freedesktop.org/mailman/listinfo/systemd-devel<br></blockquote></div><br><div> <div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div style="color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>Best Regards</div><div>Per Bergqvist</div><div><br></div><div>Managing Director<br></div><div>Bergqvist Software Technologies </div><div><br></div><div>Mobile: + 352 691 686 600</div><div><br></div></div><div><br></div></div><br class="Apple-interchange-newline"></div><br class="Apple-interchange-newline"><br class="Apple-interchange-newline"> </div> <br></div></body></html>