On 11/07/2014 10:04 AM, Bart Van Assche wrote: > On 08/21/14 21:31, Hannes Reinecke wrote: >> On 08/21/2014 06:37 PM, Bart Van Assche wrote: >>> Hannes Reinecke <hare <at> suse.de> writes: >>>> Multipath can only handle device properly which support the VPD >>>> page 0x83. Originally this was ensured by 'scsi_id', which would >>>> not present an ID_SERIAL value in these cases. >>>> With the move to udev 'ID_SERIAL' is now always present, so >>>> multipath would try to attach to _all_ SCSI devices. >>>> This patch implements an 'property' blacklist, which allows to >>>> blacklist a device based on the existence of udev properties. >>>> Any device not providing the udev property from the whitelist >>>> will be ignored. >>>> The default whitelist is set to '(ID_WWN|ID_SCSI_VPD)'. >>>> >>>> [ ... ] >>> >>> (replying to an e-mail of one year ago) >>> >>> Hello Hannes, >>> >>> I have a question about this patch. Which software component should >>> set the >>> ID_SCSI_VPD parameter ? Is it udev, now integrated in systemd ? I'm >>> asking >>> this because I haven't found any patch in the udev nor in the >>> systemd >>> repositories that sets the ID_SCSI_VPD parameter. Does this mean >>> that >>> another parameter should be used to restore support for SCSI >>> devices that >>> support the VPD page 0x83 but do not report a WWN in that page ? >>> Or does >>> this mean that systemd should be modified such that it sets the >>> ID_SCSI_VPD parameter ? >> >> That's actually simple typo. ID_SCSI_VPD was generated by one of the >> earlier instances of the sg3_utils udev rules. >> It should read 'SCSI_IDENT_LUN', as this is what the current udev >> rules >> from sg3_utils generate. >> I have a patch queued in my sles12 patchset; but so far haven't found >> time to clean them up and send upstream. >> Will be doing so once sles12 is done... > > (replying to an e-mail of two months ago) > > Hello Hannes, > > Have you already been able to free up some time to revisit what has > been discussed above ? > Not yet. I actually have avoided this issue, as multipath support with systemd is a _really_ convoluted mess. Plus there is an odd latency increase when doing a reconfiguration (a 'resume' device-mapper ioctl can take up to 0.5 seconds !) which I first need to chase down. I've already sent a patch for this, but it only covers the initial configuration; still need to have a look into the reconfiguration stuff. But yeah, I need to got through the patches and work on sending them upstream. In the meantime my patches can be found as usual under github.com:/hreinecke/multipath-tools Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 21284 (AG Nürnberg) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
