[dm-devel] path priorities on Sun's 6140

James Fillman JFillman at cucbc.com
Mon Sep 17 18:17:53 UTC 2007


Thanks for getting back to me Tore, Hannes, and Eckebrecht.

I've downloaded and installed the latest device-mapper-multipath rpm
from Redhat. It's still only beta but I figured I give it a try. I see
that there's an rdac checker in there but I don't see a hardware
handler.

Is anyone running RHEL against a Sun 6140 SAN? Trying to get a
definitive answer from Redhat on their support for this SAN has been
impossible. The mailing list hasn't been too helpful either.

If RDAC is the way to go
  1. do I need to use a hardware handler? There doesn't seem to be one
in their latest RPM.
  2. What Host type do I chose on the SAN?
  3. What should the path grouping policy by? Tore: you mentioned using
group_by_serial
  4. What should the path checker be?

I'm going to take a stab at it and guess this, can anyone confirm?:
/etc/multipath.conf

defaults
{
        udev_dir                /dev
        polling_interval        10
        selector                "round-robin 0"
        path_grouping_policy    group_by_serial
        getuid_callout          "/sbin/scsi_id -g -u -s /block/%n"
        prio_callout            "/sbin/mpath_prio_rdac /dev/%n"
        path_checker            tur
        rr_min_io               100
        rr_weight               uniform
        failback                immediate
        no_path_retry           queue
        user_friendly_name      yes
}
devices
{
        device
        {
                vendor                  "SUN"
                product                 "CSM200_R"
                path_grouping_policy    group_by_prio
                path_checker            tur
                prio_callout            "/sbin/mpath_prio_rdac /dev/%n"
                getuid_callout          "/sbin/scsi_id -g -u -s
/block/%n"
                rr_weight               uniform
                rr_min_io               1000
                features                "1 queue_if_no_path"
        }
}

cheers,
--james





More information about the dm-devel mailing list