Ceating a large file for backup and restore purpouses

dd if=/dev/zero of=100GB.FILE bs=10k count=10000000 <- Optimale Komprimierung möglich 8-)
dd if=/dev/urandom of=100GB.RANDOM.FILE bs=10k count=10000000

dd if=/dev/zero of=/dev/sdd bs=1G count=1 oflag=direct

Preparation of 1 or more hard disks for LVM

pvcreate /dev/sda /dev/mapper/myname 

Creating a VolumeGroup

vgcreate -s 4M vgname /dev/sda /dev/mapper/myname

Configuring a Logical Volume in the Group

lvcreate -l100% -n lvol01 vgname

mount -t xfs device mountpoint

dry run, verbosity level 2:

multipath -v2 -d

list configured devices

multipath -ll

/etc/multipath.conf - set userfriendly names for devices

## Use user friendly names, instead of using WWIDs as names.
defaults {
       user_friendly_names yes
#       multipath_tool  "/sbin/multipath -v0"
#       udev_dir        /dev
#      polling_interval 10
#       default_selector        "round-robin 0"
#       default_path_grouping_policy    failover
#       default_getuid_callout  "/sbin/scsi_id -g -u -s /block/%n" 
#        default_prio_callout    "/bin/true"
#       default_features        "0"
#       rr_min_io               100
       failback                immediate
}
devices {
  device {
      vendor "DGC "
      product "LUNZ            "
      path_grouping_policy group_by_priority
      getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
      prio_callout    "/sbin/mpath_prio_emc /dev/%n"
      path_checker    emc_clariion
      path_selector   "round-robin 0"
      features        "0"
      #features        "1 queue_if_no_path"
      hardware_handler "1 emc"
  }
}
# die einzelnen LUNs mit sprechenden Namen
multipaths {
      multipath {
              wwid    360060160113127004648e477123145678
              alias   meineLUN1
      }
} 
# hier alle devices listen die nicht ueber multipathing genutzt werden sollen
devnode_blacklist {
      wwid 3600508e0000000003ce93cc6b29deb04
      devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st|sda)[0-9]*"
      devnode "^hd[a-z][0-9]*"
}
# Sicherstellen, dass die Clariion nicht dabei ist
blacklist_exceptions {
      device {
              vendor  "DGC "
              product "LUNZ            "
      }
}

• Befehle zum überprüfen der korrekten Einstellungen:

Sicherstellen, dass die devices richtig erkannt werden.

myserver:/ # rescan_scsi_bus … … Scanning for device 9 0 1 0 … OLD: Host: scsi9 Channel: 00 Id: 01 Lun: 00

    Vendor: DGC      Model: LUNZ             Rev: 0429
    Type:   Direct-Access                    ANSI SCSI revision: 04

Scanning for device 9 0 1 1 … OLD: Host: scsi9 Channel: 00 Id: 01 Lun: 01

    Vendor: DGC      Model: RAID 5           Rev: 0429
    Type:   Direct-Access                    ANSI SCSI revision: 04

Scanning for device 9 0 1 2 … NEW: Host: scsi9 Channel: 00 Id: 01 Lun: 02

    Vendor: DGC      Model: RAID 5           Rev: 0429
    Type:   Direct-Access                    ANSI SCSI revision: 04

4 new device(s) found. 0 device(s) removed.

tuxbox:/sys/class/fc_host/host10 # ll
total 0
-r--r--r-- 1 root root 4096 Aug 27 08:59 active_fc4s
lrwxrwxrwx 1 root root    0 Aug 27 08:59 device -> ../../../devices/pci0000:00/0000:00:0b.0/0000:08:00.0/host1
-r--r--r-- 1 root root 4096 Aug 27 08:59 fabric_name
--w------- 1 root root 4096 Aug 27 08:59 issue_lip
-r--r--r-- 1 root root 4096 Aug 27 08:59 maxframe_size
-r--r--r-- 1 root root 4096 Aug 27 08:59 node_name
-r--r--r-- 1 root root 4096 Aug 27 08:59 port_id
-r--r--r-- 1 root root 4096 Aug 27 08:59 port_name
-r--r--r-- 1 root root 4096 Aug 27 08:59 port_state
-r--r--r-- 1 root root 4096 Aug 27 08:59 port_type
-r--r--r-- 1 root root 4096 Aug 27 08:59 speed
drwxr-xr-x 2 root root    0 Aug 27 09:00 statistics
-r--r--r-- 1 root root 4096 Aug 27 08:59 supported_classes
-r--r--r-- 1 root root 4096 Aug 27 08:59 supported_fc4s
-r--r--r-- 1 root root 4096 Aug 27 08:59 supported_speeds
-rw-r--r-- 1 root root 4096 Aug 27 08:59 tgtid_bind_type
--w------- 1 root root 4096 Aug 27 08:59 uevent