I verified that this bug is *NOT* fixed by trying the exact identical configuration (which is as minimal as possible) both with Ubuntu Trusty and with Scientific Linux 6 (RHEL6 clone). The test machine is a Cisco B200M2 blade server, using the Cisco VIC FCoE HBA (fnic.ko driver). The storage array is an EMC VNX5300, which is reached via FCoE (inside the Cisco UCS infrastructure) and then traditional FC fabric. The following console output is taken with Trusty installed. Note that it was fully upgraded. After creating /etc/multipath.conf with the indicated contents, update-initramfs was run and the system rebooted, just to make sure the settings had taken effect. As you can see from the output, the dev_loss_tmo and fast_io_fail_tmo settings are *NOT* applied: =-=-=-=-=-=-=-= tore@ucstest-osl2:~$ cat /etc/multipath.conf devices { device { vendor ".*" product ".*" fast_io_fail_tmo 3 dev_loss_tmo 2147483647 } } multipaths { multipath { wwid 3600601603a71320022967e0a1f38e411 alias bootvolume } } tore@ucstest-osl2:~$ sudo multipath -ll bootvolume (3600601603a71320022967e0a1f38e411) dm-0 DGC,VRAID size=50G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw |-+- policy='round-robin 0' prio=1 status=active | |- 0:0:1:0 sdb 8:16 active ready running | `- 1:0:1:0 sdd 8:48 active ready running `-+- policy='round-robin 0' prio=0 status=enabled |- 1:0:0:0 sdc 8:32 active ready running `- 0:0:0:0 sda 8:0 active ready running tore@ucstest-osl2:~$ grep . /sys/class/fc_remote_ports/rport-*/*tmo /sys/class/fc_remote_ports/rport-0:0-0/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-0:0-0/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-0:0-1/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-0:0-1/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-0:0-2/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-0:0-2/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-1:0-0/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-0/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-1:0-1/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-1/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-1:0-2/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-2/fast_io_fail_tmo:off tore@ucstest-osl2:~$ uname -r 3.13.0-62-generic tore@ucstest-osl2:~$ md5sum /etc/multipath.conf 27a62898e80a0bcd7e62b5f2e8d675ff /etc/multipath.conf tore@ucstest-osl2:~$ echo 3 | sudo tee /sys/class/fc_remote_ports/rport-*/fast_io_fail_tmo 3 tore@ucstest-osl2:~$ echo 2147483647 | sudo tee /sys/class/fc_remote_ports/rport-*/dev_loss_tmo 2147483647 tore@ucstest-osl2:~$ grep . /sys/class/fc_remote_ports/rport-*/*tmo /sys/class/fc_remote_ports/rport-0:0-0/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-0:0-0/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-0:0-1/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-0:0-1/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-0:0-2/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-0:0-2/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-1:0-0/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-1:0-0/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-1:0-1/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-1:0-1/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-1:0-2/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-1:0-2/fast_io_fail_tmo:3 tore@ucstest-osl2:~$ dpkg -l multipath-tools Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-======================================-========================-========================-================================================================================= ii multipath-tools 0.4.9-3ubuntu7.4 amd64 maintain multipath block =-=-=-=-=-=-=-= This shows the exact same multipath.conf file being used on SL6, and in this case the sysfs settings *ARE* applied when the multipath map is registered (no reboot required): =-=-=-=-=-=-=-= [root@ucstest-osl2 ~]# uname -r 2.6.32-358.23.2.el6.x86_64 [root@ucstest-osl2 ~]# rpm -qa device-mapper-multipath device-mapper-multipath-0.4.9-80.el6.x86_64 [root@ucstest-osl2 ~]# grep . /sys/class/fc_remote_ports/rport-*/*tmo /sys/class/fc_remote_ports/rport-1:0-0/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-0/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-1:0-1/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-1/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-1:0-2/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-2/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-2:0-0/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-2:0-0/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-2:0-1/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-2:0-1/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-2:0-2/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-2:0-2/fast_io_fail_tmo:off [root@ucstest-osl2 ~]# md5sum /etc/multipath.conf 27a62898e80a0bcd7e62b5f2e8d675ff /etc/multipath.conf [root@ucstest-osl2 ~]# multipath -v 2 Aug 26 07:06:34 | 35000c50042a362cb: ignoring map create: bootvolume (3600601603a71320022967e0a1f38e411) undef DGC,VRAID size=50G features='0' hwhandler='0' wp=undef |-+- policy='round-robin 0' prio=1 status=undef | `- 1:0:0:0 sdb 8:16 undef ready running |-+- policy='round-robin 0' prio=1 status=undef | `- 1:0:1:0 sdc 8:32 undef ready running |-+- policy='round-robin 0' prio=1 status=undef | `- 2:0:0:0 sdd 8:48 undef ready running `-+- policy='round-robin 0' prio=1 status=undef `- 2:0:1:0 sde 8:64 undef ready running [root@ucstest-osl2 ~]# grep . /sys/class/fc_remote_ports/rport-*/*tmo /sys/class/fc_remote_ports/rport-1:0-0/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-1:0-0/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-1:0-1/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-1:0-1/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-1:0-2/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-1:0-2/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-2:0-0/dev_loss_tmo:30 /sys/class/fc_remote_ports/rport-2:0-0/fast_io_fail_tmo:off /sys/class/fc_remote_ports/rport-2:0-1/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-2:0-1/fast_io_fail_tmo:3 /sys/class/fc_remote_ports/rport-2:0-2/dev_loss_tmo:2147483647 /sys/class/fc_remote_ports/rport-2:0-2/fast_io_fail_tmo:3 =-=-=-=-=-=-=-= Tore