[dm-devel] Re: Problems with path groups in multipath-tools

[Juha Koivisto]

I'm not sure if my previous message is going to make it to the list (by
now it hasn't yet, at least according to the web archive), but I solved
my problem already. It turns out that in order to use a shell script as
prio_callout (in multipath.conf), the command needs to be explicitly
executed with /bin/sh.

This works (at least for me):

/etc/multipath.conf:
---cut---
devices {
        device {
                vendor                  "DGC     "
                product                 "*"
                path_grouping_policy    group_by_prio
                prio_callout            "/bin/sh /usr/local/sbin/get_path_prio %n"
                #getuid_callout         "/sbin/scsi_id -g -s /block/%n"
                #path_checker           emc_clariion
                path_selector           "round-robin 0"
                hardware_handler        "1 emc"
        }
}
---cut---

/usr/local/sbin/get_path_prio:
---cut---
#/bin/sh

PATH=/bin:/usr/bin

prio=1
if [ -e /sys/block/$1/device ]; then
        target=`ls -l /sys/block/$1/device | tr / "\n" | grep target.:.:`
        if [ -e /sys/class/fc_transport/$target/port_name ]; then
                id=`cut -c 10 < /sys/class/fc_transport/$target/port_name`
                case $id in
                        0 | 1 | 2 | 3 )
                                prio=1
                                ;;
                        8 | 9 | a | b | A | B )
                                prio=2
                                ;;
                esac
        fi
fi

echo $prio
---cut---

I don't know if I should use emc_clarion as path_checker (it sees the
non-active paths as "ready", while the default readsector0 reports them
as faulty), but I guess that's not very important right now.

Please Cc: me in replies, I'm not subscribed to the list.

-- 
Juha.Koivisto at hut.fi