multipath.conf

# http://linux-itpro.blogspot.com.ar/2015/04/instalacion-de-proxmox-con-multipath-y.html
# https://pve.proxmox.com/wiki/ISCSI_Multipath#Dell
# http://www.dell.com/downloads/global/products/pvaul/en/powervault-md32x0-md32x0i-linux-dm-installation-en.pdf
# http://www.dell.com/downloads/global/products/pvaul/en/powervault-md3200i-performance-tuning-white-paper.pdf
defaults {
        user_friendly_names yes

    # Specify  the  maximum number of file descriptors that
    # can be opened by multipath and multipathd.  This is
    # equivalent to ulimit -n. A value
        # of max will set this to the system limit from
    # /proc/sys/fs/nr_open. If this is not set, the maximum
    # number of open fds is taken  from  the
        # calling process. It is usually 1024. To be safe, this
    # should be set to the maximum number of paths plus 32,
    # if that number is greated than 1024
        max_fds             8192

        # queue_without_daemon  thout_daemon
        # If set to no , when multipathd stops, queueing will be
    # turned off  for  all  devices.   This  is  useful  for
    # devices  that set no_path_retry.  If a machine is shut
    # down while all paths to a device are down, it is  pos‐
    #  sible to hang waiting for IO to return from the device
    # after multipathd has been stopped. Without  multipathd
    # running,  access  to the paths cannot be restored, and
    # the kernel cannot be told to stop queueing IO. Setting
    # queue_without_daemon  to  no  ,  avoids  this problem.
    #Default is yes
        queue_without_daemon  no

    # interval between two path checks in seconds. For prop‐
    # erly  functioning  paths,  the interval between checks
    # will gradually increase to max_polling_interval.  This
    # value will be overridden by the WatchdogSec setting in
    # the multipathd.service definition if systemd is  used.
    # Default is 5
        polling_interval        5 # era 2

        path_selector           "round-robin 0"
        path_grouping_policy    multibus

    # porque deprecated
        # getuid_callout          "/lib/udev/scsi_id -g -u -d /dev/%n"

    # The number of IO to route to a path  before  switching
    # to the  next in the same path group. This is only for
    #  BIO based multipath. Default is 1000
        rr_min_io               100

    #  failback         Tell multipathd how to manage path group failback.
        #       immediate   Immediately failback to the highest prior‐
        #       ity pathgroup that contains active paths.
    # Default value is manual.
        failback                immediate

    # no_path_retry  Specify  the number of retries until disable queueing
    #              or fail for immediate failure (no queueing), queue for
    #              never   stop   queueing.   If  unset  no  queueing  is
    #              attempted.  Default is unset.
        no_path_retry           queue
}


blacklist {
        wwid .* # Blacklistamos todo para que no se armen paths fuera d ctrl
        # devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
        # devnode "^hd[a-z][[0-9]*]"
}

blacklist_exceptions {
        # excepciones de blacklist (discosu/bloques en el storage)
        wwid "3600a098000a5bfe50000029a582e9dc4"
        wwid "3600a098000a5bfe50000029d582e9e10"
}


devices {
        device {
                vendor                "DELL"
                product               "MD38xxf"

        # path_grouping_policy
        #   The  default path grouping policy to apply to unspeci‐
        #       fied multipaths. Possible values a
        #   group_by_prio
        #                   1 priority group per priority value.  Pri‐
        #                   orities are determined by callout programs
        #                   specified as a global,  per-controller  or
        #                   per-multipath  option in the configuration
        #                   file.
                path_grouping_policy  group_by_prio


        # The name of the path priority routine.  The  specified
        # routine  should  return a numeric value specifying the
        # relative priority of this path. Higher number  have  a
        # higher priority.  none is a valid value. Currently the
        # following path priority routines are implemented:
        #   rdac   Generate the path priority  for  LSI/Enge‐
        #          nio/NetApp E-Series RDAC controller
                prio                  rdac

        # ver más arriba
        # dejo comentado porque multipath -v2 no reconoce el término
        # polling_interval      5

        # The default method used to determine the paths  state.
            # Possible values are
        #   rdac        Check  the  path   state   for   LSI/Enge‐
        #               nio/NetApp   E-Series  RDAC  storage  con‐
        #               troller
                path_checker          rdac

        # ver arriba
                path_selector         "round-robin 0"

        # hardware_handler (Optional) The hardware handler to use
        # for this device
        #   type.  The following hardware handler are implemented:
        #   1 rdac      Hardware handler for LSI/Engenio/NetApp E-
        #               Series RDAC storage controller.
                hardware_handler      "1 rdac"

        # ver más arriba
                failback              immediate

        # Specify any device-mapper features to be used.  Syntax
        # is  num  list  where  num is the number of features in
        # list.
                features              "2 pg_init_retries 50"

        # Specify  the number of retries until disable queueing,
        # or fail for immediate failure (no queueing), queue for
        # never   stop   queueing.   If  unset  no  queueing  is
        # attempted.  Default is unset.
                no_path_retry         30

        # The number of IO to route to a path  before  switching
        # to  the  next in the same path group. This is only for
        # BIO based multipath. Default is 1000
                rr_min_io             100
        }
}
multipaths {
        multipath {
                wwid "3600a098000a5bfe50000029d582e9e10"
                alias DiscoTest2
        }
        multipath {
                wwid "3600a098000a5bfe50000029a582e9dc4"
                alias DiscoTest
        }
}
# End Dell MD Modification