multipathing on linux

1. check file ni tgk entry ni dah disable ke belum

[server mpath]# more /etc/multipath.conf# Blacklist all devices by default. Remove this to enable multipathing# on the default devices.#devnode_blacklist {# devnode "*"#}

2. buat step ni utk recreate / refresh multipath

[server mpath]# chkconfig multipathd on
[server mpath]# modprobe dm-multipath
[server mpath]# modprobe dm-round-robin
[server mpath]# cd /etc/init.d
[server init.d]# ./multipathd restart


2 step ni utk create multipath


untuk check disk,after restart multipath

1. [server mpath]# ll /dev/mpath
check entry ada tak macam ni

# lltotal 0lrwxrwxrwx 1 root root 7 Jul 15 11:06 [00;36m360060480000190105137533032334630[00m -> [40;33;01m../dm-8[00mlrwxrwxrwx 1 root root 8 Jul 15 11:06 [00;36m360060480000190105137533032343030[00m -> [40;33;01m../dm-10[00mlrwxrwxrwx 1 root root 8 Jun 20 07:02 [00;36mSAN-disk100m -> 40;33;01m../dm-20[00mlrwxrwxrwx 1 root root 8 Jun 20 07:02 [00;36mSAN-disk1000m -> 40;33;01m../dm-23[00m

2 line atas tu disk baru ( belum configure)
2 line yang bawah tu disk lama ( dah configure)


utk tau raw disk ni nnt assign kat mana, check koman ni
# multipath -ll
SAN-disk16 (360060480000190105137533032333130)[size=67 GB][features="0"][hwhandler="0"]\_ round-robin 0 [active] \_ 4:0:0:58 sdax 67:16 [active][ready] \_ 2:0:0:58 sdr 65:16 [active][ready]
SAN-disk15 (360060480000190105137533032353038)[size=67 GB][features="0"][hwhandler="0"]\_ round-robin 0 [active] \_ 4:0:0:49 sdaw 67:0 [active][ready] \_ 2:0:0:49 sdq 65:0 [active][ready]
SAN-disk27 (360060480000190105137533032343030)[size=67 GB][features="0"][hwhandler="0"]\_ round-robin 0 [active] \_ 2:0:0:70 sdad 65:208 [active][ready] \_ 4:0:0:70 sdbj 67:208 [active][ready]
SAN-disk26 (360060480000190105137533032334630)[size=67 GB][features="0"][hwhandler="0"]\_ round-robin 0 [active] \_ 2:0:0:68 sdab 65:176 [active][ready] \_ 4:0:0:68 sdbh 67:176 [active][ready]


so dari situ awak kena matchkan

lrwxrwxrwx 1 root root 7 Jul 15 11:06 [360060480000190105137533032334630 -> [40;33;01m../dm-8[00m
sebenanya sama dengan
SAN-disk26 (360060480000190105137533032334630)[size=67 GB][features="0"][hwhandler="0"]\_ round-robin 0 [active] \_ 2:0:0:68 sdab 65:176 [active][ready] \_ 4:0:0:68 sdbh 67:176 [active][ready]
after tu kena crete disk

ni step utk create disk

# fdisk /dev/sdab Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabelBuilding a new DOS disklabel. Changes will remain in memory only,until you decide to write them. After that, of course, the previouscontent won't be recoverable.
The number of cylinders for this disk is set to 8803.There is nothing wrong with that, but this is larger than 1024,and could in certain setups cause problems with:1) software that runs at boot time (e.g., old versions of LILO)2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK)Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): p <<<----- check dulu disk dah assign belum. kalau tgk kat sini dia belum assign so boleh proceed Disk /dev/sdab: 72.4 GB, 72414658560 bytes255 heads, 63 sectors/track, 8803 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System Command (m for help): n <<------- n utk newCommand action e extended p primary partition (1-4) p <<------ p untuk primary Partition number (1-4): 1 <<----------- tekan 1 First cylinder (1-8803, default 1): 1Using default value 1Last cylinder or +size or +sizeM or +sizeK (1-8803, default 8803): Using default value 8803 Command (m for help): p <<--------------check balik tgk disk dah assign. tapi system type still linux. kena tuka LVM Disk /dev/sdab: 72.4 GB, 72414658560 bytes255 heads, 63 sectors/track, 8803 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System/dev/sdab 1 8803 70710066 83 Linux Command (m for help): t <<---------- type t untuk tukar (type)Selected partition 1Hex code (type L to list codes): 8e <<------------------ code LVM 8e. nak tgk code lain type lChanged system type of partition 1 to 8e (Linux LVM) Command (m for help): p << ------------------- check balik skang dia dah tuka LVM Disk /dev/sdab: 72.4 GB, 72414658560 bytes255 heads, 63 sectors/track, 8803 cylindersUnits = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System/dev/sdab 1 8803 70710066 8e Linux LVM Command (m for help): w <<-------------------- ni utk save configurationThe partition table has been altered! Calling ioctl() to re-read partition table.Syncing disks.# lepas tu continue utk disk2 yang lain after create disk semua, buat macam biasa # vgextend VolGroup01 /dev/mpath/SAN-diskxxx ( check SAN-disk kat /dev/mpath) # lvcreate -L 544G /dev/VolGroup01 -n ou08_vol # mkfs -t ext3 -m0 /dev/VolGroup01/ou08_vol # mkdir /oracle/u08 # chown oracle:dba /oracle/u08 # chmod 770 /oracle/u08 # mount /dev/VolGroup01/ou08_vol /oracle/u08 # chmod 770 /oracle/u08 # df -h /oracle/u08 Filesystem Size Used Avail Use% Mounted on /dev/mapper/VolGroup01-ou08_vol 536G 102M 536G 1% /oracle/u08 # vi /etc/fstab If tak jadi try run koman ni : Run command nie echo 1 > /sys/class/fc_host/host/issue_lip
echo "- - -" > /sys/class/scsi_host/host/scan


nk tau ape, ls –lrt under /sys/class/fc_host and /sys/class/scsi_host/. If ade host0, host1, etc, so kene run one by one..
pastu restart service, then nmpk..

[server init.d]# multipath -ll

mpath38 (360060480000290101604533031363238)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:60 sdca 68:224 [active][ready]
\_ 4:0:0:60 sdci 69:96 [active][ready]

mpath40 (360060480000290101604533031363438)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:64 sdce 69:32 [active][ready]
\_ 4:0:0:64 sdcm 69:160 [active][ready]

mpath45 (360060480000290101604533031363230)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:59 sdbz 68:208 [active][ready]
\_ 4:0:0:59 sdch 69:80 [active][ready]

mpath44 (360060480000290101604533031363330)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:61 sdcb 68:240 [active][ready]
\_ 4:0:0:61 sdcj 69:112 [active][ready]

mpath43 (360060480000290101604533031363138)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:58 sdby 68:192 [active][ready]
\_ 4:0:0:58 sdcg 69:64 [active][ready]

mpath42 (360060480000290101604533031363338)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:62 sdcc 69:0 [active][ready]
\_ 4:0:0:62 sdck 69:128 [active][ready]

mpath39 (360060480000290101604533031363430)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:63 sdcd 69:16 [active][ready]
\_ 4:0:0:63 sdcl 69:144 [active][ready]

mpath41 (360060480000290101604533031363130)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:57 sdbx 68:176 [active][ready]
\_ 4:0:0:57 sdcf 69:48 [active][ready]



=====================================================

Wahai rakyat jelata sekalian,

Kalau dah buat steps bawah ni tapi disk still tak nampak,
Boleh scan guna cara ni :


Run command nie 
echo 1 > /sys/class/fc_host/host/issue_lip
echo "- - -" > /sys/class/scsi_host/host/scan


nk tau ape, ls –lrt under /sys/class/fc_host and /sys/class/scsi_host/. If ade host0, host1, etc, so kene run one by one..
pastu restart service, then nmpk..

[root@server init.d]# multipath -ll

mpath38 (360060480000290101604533031363238)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:60 sdca 68:224 [active][ready]
\_ 4:0:0:60 sdci 69:96 [active][ready]

mpath40 (360060480000290101604533031363438)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:64 sdce 69:32 [active][ready]
\_ 4:0:0:64 sdcm 69:160 [active][ready]

mpath45 (360060480000290101604533031363230)
[size=67 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=2][active]
\_ 2:0:0:59 sdbz 68:208 [active][ready]
\_ 4:0:0:59 sdch 69:80 [active][ready]