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Linux multipath-tools with EMC CX3-40

·209 words·1 min
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Howto use EMC CX3-40 with Linux multipath-tools #

Running Ubuntu 6.06.1 LTS on an EMC Clariion CX3-40 is actually quite simple. Why EMC Powerpath, if there are also the multipath-tools (*is of course not supported). Here are the necessary configs:

Configuration /etc/multipath.conf #

The blacklist lists all device names that must not be used by multipath, e.g. the internal system discs (/dev/sda … /dev/sdf):

blacklist {
        devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
        devnode "^hd[a-z][[0-9]*]"
        devnode "^sd[a-g][[0-9]*]"
        devnode "^hda[0-9]*"
        devnode "^cciss!c[0-9]d[0-9]*[p[0-9]*]"
        devnode "sd[a-f]$"   // internal disks
}

The CX3-40 reports under the name “DGC”:

devices {
   device {
      vendor                  "DGC"
      product                 "RAID 5"
      path_grouping_policy    group_by_prio
      prio_callout            "/sbin/mpath_prio_emc /dev/%n"
      getuid_callout          "/lib/udev/scsi_id -g -s /block/%n"
      path_checker            emc_clariion
      features                "1 queue_if_no_path"
      no_path_retry           300
      hardware_handler        "1 emc"
      failback                immediate
      product_blacklist       "LUNZ"
   }
}

multipaths {
    # Storage 1, LUN 21
    multipath {
         wwid 3600601642d93190004d1fe31xxxxxxxxx
         alias                   rr1-lun21
         path_grouping_policy    failover
         failback                immediate
    }
    # Storage 3, LUN 22
    multipath {
         wwid 3600601642b9319004da05984xxxxxxxx
         alias                   rr3-lun22
         path_grouping_policy    failover
         failback                immediate
    }
}