Hello, I am doing some tests with SLES10 SP2 beta4 and an IBM DS4700 Storage system, particularly focusing on DM-MP with the DS4000. When configuring DM-MP I get inconsistent results when running multipath with various options. I also have a problem with path fail back, which I will describe in a separate mail to avoid confusion. Here's the setup: - IBM System x 3650 server with 2 QLA2460 HBAs - SLES10 SP2 beta4 X86_64 installed on internal disk - kernel-smp-2.6.16.60-0.6 - multipath-tools-0.4.7-34.32 - qla2xxx 8.02.00-k6-SLES10.2-02 - Brocade B32 4Gb switch, zoned that each HBA can see one DS4700 controller - DS4700 presenting a 50 GB LUN to the server Another system is equipped with 2 Emulex LP1150 HBAs, running lpfc 8.2.0.19. All the rest is the same as above. I looked at the HW table of the multipath tools: device { vendor "IBM" product "1814" path_grouping_policy "group_by_prio" path_checker "rdac" hardware_handler "1 rdac" prio "rdac" no_path_retry "queue" } and decided that the internal defaults are ok for me with 2 exceptions: - I want immediate automatic fail back - I don't want "queue if no path". So my "/etc/multipath.conf" is quite simple and looks like this: x3650-lab-11:~ # cat /etc/multipath.conf defaults { no_path_retry 300 features "0" failback immediate user_friendly_names yes } blacklist { devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*" devnode "^hd[a-z][[0-9]*]" devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]" wwid SServeRA_Daten_6673ADC0 wwid SServeRA_OS_77F79DC0 } Here are the outputs of multipath with various options. Look at the priority values and the [features=...] statement. BTW - the results are the same on the machine with LPFC HBAs and also if I use the mpath_prio_rdac callout. Dry-Run ------- x3650-lab-11:~ # multipath -d create: mpatha (3600a0b800011fa78000033d947d7650d) n/a IBM,1814 FAStT [size=50G][features=0][hwhandler=1 rdac] \_ round-robin 0 [prio=2][undef] \_ 4:0:0:0 sdd 8:48 [undef][ghost] \_ round-robin 0 [prio=1][undef] \_ 3:0:0:0 sdc 8:32 [undef][ready] Configure DM-MP --------------- x3650-lab-11:~ # multipath create: mpatha (3600a0b800011fa78000033d947d7650d) n/a IBM,1814 FAStT [size=50G][features=0][hwhandler=1 rdac] \_ round-robin 0 [prio=2][undef] \_ 4:0:0:0 sdd 8:48 [undef][ghost] \_ round-robin 0 [prio=1][undef] \_ 3:0:0:0 sdc 8:32 [undef][ready] Show multipath topology (sysfs and DM info) ------------------------------------------- x3650-lab-11:~ # multipath -l mpatha (3600a0b800011fa78000033d947d7650d) dm-0 IBM,1814 FAStT [size=50G][features=1 queue_if_no_path][hwhandler=1 rdac] \_ round-robin 0 [prio=-1][active] \_ 4:0:0:0 sdd 8:48 [active][undef] \_ round-robin 0 [prio=-1][enabled] \_ 3:0:0:0 sdc 8:32 [active][undef] Show multipath topology (maximum info) -------------------------------------- x3650-lab-11:~ # multipath -ll mpatha (3600a0b800011fa78000033d947d7650d) dm-0 IBM,1814 FAStT [size=50G][features=1 queue_if_no_path][hwhandler=1 rdac] \_ round-robin 0 [prio=3][active] \_ 4:0:0:0 sdd 8:48 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 3:0:0:0 sdc 8:32 [active][ghost] The resulting device mapper table looks like this x3650-lab-11:~ # dmsetup table mpatha 0 104857600 multipath 1 queue_if_no_path 1 rdac 2 1 round-robin 0 1 1 8:48 1000 round-robin 0 1 1 8:32 1000 With this said, here are my questions: - How can I avoid that "queue if no path" is set? - Am I using an outdated version of multipath? - Which of the different outputs is the correct one? - What is the true configuration (I can't "read" the dm table)? - Are the differences in output a bug or are they correct and I can't interpret them? Many thanks in advance ........... Alex Mit freundlichen Grüßen ... Kind regards ... Alexander Warmuth Advanced Technical Support System Storage Europe Enterprise Disk High End Solutions Mail: warmuth@xxxxxxxxxx Phone: +49-6131-84-2887 Mobile: +49-171-5506083 Request ATS support at http://web.mainz.de.ibm.com/e_dir/esccw3.nsf/ContentDocsByTitle/Request+support IBM Deutschland GmbH, Vorsitzender des Aufsichtsrats: Hans Ulrich Maerki, Geschäftsführung: Martin Jetter (Vorsitzender), Christian Diedrich, Christoph Grandpierre, Matthias Hartmann, Thomas Fell, Michael Diemer, Sitz der Gesellschaft: Stuttgart, Registergericht: Amtsgericht Stuttgart, HRB 14562, WEEE-Reg.-Nr. DE 99369940 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel