Add new disk to ASM diskgroup oracle (multipath)

ADDING NEW SAN DISK TO EXISTING ASM DISK_GROUP

First Check the current attached disks number

    #cat /proc/scsi/scsi | egrep -i 'Host:' | wc -l

 -----   #fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l

Check current multipath setup using multipath or powermt command

    # multipath -l
    mpath2 (36006016015501c0018c07c18e0d8dc11)
    [size=68 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
    \_ round-robin 0 [active]
    \_ 0:0:0:2 sdc 8:32  [active]
    \_ round-robin 0 [enabled]
    \_ 1:0:0:2 sdi 8:128 [active]

    mpath1 (36006016015501c0084227c0ee0d8dc11)
    [size=68 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
    \_ round-robin 0 [active]
    \_ 1:0:0:1 sdh 8:112 [active]
    \_ round-robin 0 [enabled]
    \_ 0:0:0:1 sdb 8:16  [active]

    mpath0 (36006016015501c00b6de3705e0d8dc11)
    [size=68 GB][features="1 queue_if_no_path"][hwhandler="1 emc"]
    \_ round-robin 0 [active]
    \_ 0:0:0:0 sda 8:0   [active]
    \_ round-robin 0 [enabled]
    \_ 1:0:0:0 sdg 8:96  [active]

  
>>>>>Scan for LUNS (in all nodes of RAC)

    Note this is for 2.6 kernel

    # ls /sys/class/fc_host
    host0  host1
  
    #echo "1" > /sys/class/fc_host/host0/issue_lip
    #echo "1" > /sys/class/fc_host/host1/issue_lip
  
another time check multipath -l to check new multipath that founded

for creating alias for multipath you can edit /etc/multipath.conf and add new multipath like below (in all nodes of RAC)

    blacklist {
     devnode "^(ramrawloopfdmddm-srscdst)[0-9]*"
     devnode "^hd[a-z]"
     devnode "^cciss!c[0-9]d[0-9]*"
     }

    multipaths {
     multipath {
     wwid  3600c0ff00025f69165c4975601000000
     alias data001
     path_grouping_policy failover
     }
     multipath {
     wwid  3600c0ff00025f691a9539b5601000000
     alias fra001
     path_grouping_policy failover
     }
     multipath {
     wwid  3600c0ff00025f69243539b5601000000
     alias new_multipth_alias
     path_grouping_policy failover
     }
    }

after edit multipath.conf , reload multipath: (in all nodes of RAC)

    service multipathd reload
  

format new disk by fdisk:

    fdiak /dev/mapper/new_multipath_alias    and  so..... n p 1 w
  
create new oracleasm disk

        oracleasm listdisks
        oracleasm createdisk new_disk_name /dev/mapper/new_multipath_alias

        oracleasm listdisks

log in to sqlplus by sysasm and grid user and find new disk path

        GRID>sqlplus / as sysasm
      
        SQL>select GROUP_NUMBER,DISK_NUMBER,STATE,name,path,MOUNT_STATUS,HEADER_STATUS from v$asm_disk;
      
        GROUP_NUMBER DISK_NUMBER STATE NAME PATH MOUNT_S HEADER_STATU
        ———— ———– ——– ————– ——————————— ——- ————
        0 0 NORMAL /dev/oracleasm/disks/ARC_LOG02 CLOSED PROVISIONED
        2 0 NORMAL ARC_LOG_0000 /dev/oracleasm/disks/ARC_LOG01 CACHED MEMBER
        1 0 NORMAL OCR_VOTE_0000 /dev/oracleasm/disks/OCR_VOTE01 CACHED MEMBER
        3 4 NORMAL DB_DATA_0004 /dev/oracleasm/disks/new_disk_name CACHED MEMBER
      
        or maybe
      
        GROUP_NUMBER DISK_NUMBER STATE    NAME  PATH MOUNT_S HEADER_STATU

           1           0 NORMAL   DATA001 ORCL:DATA001 CACHED  MEMBER

           2           0 NORMAL   FRA01 ORCL:new_disk_name

after that add this disk to existing disk_group:
    GRID>
    SQL>ALTER DISKGROUP ARC_LOG ADD DISK ‘/dev/oracleasm/disks/new_disk_name' NOFORCE ;
    or
    SQL>ALTER DISKGROUP ARC_LOG(oracle diskgroup name) ADD DISK ‘ORCL:new_disk_name' NOFORCE ;       →    'ORCL:data001'
  
You can verify the rebalancing operation by below SQL command.

    SQL> select * from v$asm_operation ;
    GROUP_NUMBER OPERA STAT POWER ACTUAL SOFAR EST_WORK EST_RATE EST_MINUTES ERROR_CODE
    ———— —– —- ———- ———- ———- ———- ———————————-
    1 REBAL RUN 1 1 5046 5631 4780 0