How To Add a New Disk(s) to An Existing Diskgroup on RAC Cluster or Standalone ASM Configuration (Best Practices).

How To Add a New Disk(s) to An Existing Diskgroup on RAC Cluster or Standalone ASM Configuration (Best Practices). (Doc ID 557348.1)

APPLIES TO:

Oracle Database - Enterprise Edition - Version 10.1.0.2 to 12.1.0.1 [Release 10.1 to 12.1]
Information in this document applies to any platform.

GOAL

Before you add the disk(s) to your production diskgroup, you can use the next steps to validate whether the candidate disk(s) is/are in good shape and can be accessed from each node (without harm the existing production diskgroups), as follow:

SOLUTION

1) As Oracle or Grid OS user, run the next commands on each node (if ASMLIB API is used):

# /etc/init.d/oracleasm  scandisks  #(only this command needs to be executed as root user)
$> id
$> /etc/init.d/oracleasm  listdisks
$> /etc/init.d/oracleasm  querydisk 

Note: All the disks must be visible from each node.

2) Confirm the disks are visible (I/O) at OS level (as oracle or grid OS user) from each node:

$> id
$> ls -l  
$> dd if= of=/dev/null count=100 bs=8192

Example:

$> dd if=/dev/raw/raw1 of=/dev/null count=100 bs=8192  # raw device
$> dd if=/dev/oracleasm/disks/PRODA07 of=/dev/null count=100 bs=8192  # ASMLIB device
$> dd if=/dev/rdsk/c1t3d0s6 of=/dev/null count=100 bs=8192 # raw device

3) Verify that kfed can read on the candidate disk(s) at OS level (as oracle or grid OS user) from each node:

$> kfed read 

Example:

$> kfed read /dev/raw/raw1

$> kfed read /dev/oracleasm/disks/PRODA07

$> kfed read /dev/rdsk/c1t3d0s6

Note: If the disk is not a FORMER disk, then kfed on new disks will return:    kfbh.type: 0 ; 0x002: KFBTYP_INVALID and that is expected.

 4) Create a new temporary diskgroup:

SQL> CREATE DISKGROUP TEST EXTERNAL REDUNDANCY DISK '';

5) Check if the diskgroup is created and mounted:

SQL> SELECT STATE, NAME FROM V$ASM_DISKGROUP;

6) If so, then manually mount it on the other ASM instance(s):

SQL> ALTER DISKGROUP TEST MOUNT;
SQL> SELECT STATE, NAME FROM V$ASM_DISKGROUP;

7) If the previous steps had success and the TEST diskgroup can be successfully mounted (on each ASM instance), then drop the TEST diskgroup as follow:

SQL> alter diskgroup test dismount; --(from all the ASM instances, except from one).

SQL> DROP DISKGROUP TEST; --(from the ASM instance, which the diskgroup is still mounted).

8) Then the candidate disk is ready to be added to the desired diskgroup:

SQL> ALTER DISKGROUP  ADD DISK '';

Note: The same disks validation steps are also required for ASM Standalone configurations.

Note---> This informationmation taken from oracle metalink. all copy rights oracle only.