Habilitar multipath no debian 4 e 5 utilizando o XIV

Instalar os pacotes abaixo:

# aptitude install multipath-tools-boot multipath-tools firmware-qlogic firmware-bnx2 sysfsutils
# reboot

Criar o arquivo multipath.conf com o conteudo abaixo:

###############################################################################
# Multipath.conf file for IBM Storage
# IMPORTANT: If you change multipath.conf settings after the DM MPIO devices
# have already been configured, be sure to rerun "multipath".
###############################################################################
#
#
# defaults:
#
#     polling_interval   : The interval between two path checks in seconds.
#   
#     failback           : The failback policy should be set to "immediate"
#                          to have automatic failback, i.e. if a higher
#                          priority path that previously failed is restored,
#                          I/O automatically and immediately fails back to
#                          the preferred path.
#
#    no_path_retry       : Use this setting in order to deal with transient
#                          total path failure scenarios. Indicates that the if
#                          all paths are failed for 10 checks (iterations of
#                          the checkerloop) then will set the device to
#                          .fail_if_no_path. so that I/O will not stay queued
#                          forever and I/O errors are returned back to the
#                          application. This value should be adjusted based on
#                          the value of the polling_interval. Basically, with a
#                          larger polling_interval, this means that the amount
#                          of time of allowed total path failure will be
#                          longer, since the tolerance time is
#                          (no_path_retry * polling_interval) seconds.
#                          SHOULD NOT BE USED WITH .features..
# 
#    rr_min_io           : The number of IOs to route to a path before switching
#                          to the next path in the same path group
#
#    path_checker        : The default 'readsector0' path checker uses SCSI
#                          READ (opcode 0x28) which doesn't work in clustered
#                          environments. TUR (Test Unit Ready) does work in
#                          clustered environments with storage that subscribes
#                          to the SCSI-3 spec.
#
#    user_friendly_names : With this value set to .yes., DM MPIO devices will
#                          be named as .mpath0., .mpath1., .mpath2., etc. ...
#                          The /var/lib/mulitpath/bindings file is
#                          automatically generated, mapping the .mpathX. name
#                          to the wwid of the LUN. If set to "no", use the
#                          WWID as the alias. In either case this be will be
#                          overriden by any specific aliases in this file.
#
#
defaults {
    polling_interval    30
        failback            immediate
        no_path_retry       5
        no_path_retry       5
        rr_min_io           100
        path_checker        tur
        user_friendly_names yes
        }


#
#  devices    : List of per storage controler settings, overrides default
#              settings (device_maps block), overriden by per multipath
#              settings (multipaths block)
#
#  vendor     : Vendor Name
#
#  product    : Product Name
#
#  path_grouping_policy : Path grouping policy to apply to multipath hosted
#                         by this storage controller
#
#  prio_callout : The program and args to callout to obtain a path
#              weight. Weights are summed for each path group to
#              determine the next PG to use case of failure.
#              NOTE: If no callout then all paths have equals weight.
#
#

devices {
        device {
                vendor "IBM"
                product "2810XIV"
                selector "round-robin 0"
                path_grouping_policy multibus
                rr_min_io 15
                path_checker tur
                failback 15
                no_path_retry queue
                polling_interval 3
        }

}

multipaths {
         multipath {
                  wwid <lun do disco do sistema>
                  alias system
                  path_grouping_policy failover
                  path_selector "round-robin 0"
         }



}

devnode_blacklist {
             devnode "*"
             }

blacklist {
             devnode "sda"
          }


Após a criação do arquivo, execute os comandos abaixo:

# multipath -F
# /etc/init.d/multipath-tools restart
# multipath -ll

Verifique se foi criado os dispositivos

# ls /dev/mapper/

Após isso devemos atualizar o grub.

# update-initramfs -u
# update-grub
# reboot