!! How to CREATE DISK and add asm disk on Diskgroup !!
1 . Check The disk (LUNS)
[root@oravb ~]# hostname
oravb.vbtech.com
[root@oravb ~]# fdisk -l
Disk /dev/sdc: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
[root@oravb ~]#
2. create partitions On " /dev/sdc "
[root@oravb ~]# fdisk /dev/sdc
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x60993f20.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-5221, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-5221, default 5221): 1000
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (1001-5221, default 1001):
Using default value 1001
Last cylinder, +cylinders or +size{K,M,G} (1001-5221, default 5221): 2000
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (2001-5221, default 2001):
Using default value 2001
Last cylinder, +cylinders or +size{K,M,G} (2001-5221, default 5221): 3000
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Selected partition 4
First cylinder (3001-5221, default 3001):
Using default value 3001
Last cylinder, +cylinders or +size{K,M,G} (3001-5221, default 5221):
Using default value 5221
Command (m for help): p
Disk /dev/sdc: 42.9 GB, 42949672960 bytes
255 heads, 63 sectors/track, 5221 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x60993f20
Device Boot Start End Blocks Id System
/dev/sdc1 1 1000 8032468+ 83 Linux
/dev/sdc2 1001 2000 8032500 83 Linux
/dev/sdc3 2001 3000 8032500 83 Linux
/dev/sdc4 3001 5221 17840182+ 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@oravb ~]# partprobe
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sda (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sdb (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
[root@oravb ~]#
3. CREATE ASM DISK FROM os DISKS :
[root@oravb ~]# oracleasm createdisk test1 /dev/sdc1
Writing disk header: done
Instantiating disk: done
[root@oravb ~]# oracleasm createdisk test2 /dev/sdc2
Writing disk header: done
Instantiating disk: done
[root@oravb ~]# oracleasm createdisk test3 /dev/sdc3
Writing disk header: done
Instantiating disk: done
[root@oravb ~]# oracleasm createdisk test4 /dev/sdc4
Writing disk header: done
Instantiating disk: done
Check disks :
[root@oravb ~]# oracleasm listdisks
ACFS1
ACFS2
DATA
OCR
TEST1
TEST2
TEST3
TEST4
Check disks on Os level
[root@oravb ~]# ls -altr /dev/oracleasm/disks
total 0
drwxr-xr-x. 4 root root 0 Jul 5 22:52 ..
drwxr-xr-x. 1 root root 0 Jul 5 22:52 .
brw-rw----. 1 oracle dba 8, 33 Jul 5 23:01 TEST1
brw-rw----. 1 oracle dba 8, 34 Jul 5 23:01 TEST2
brw-rw----. 1 oracle dba 8, 35 Jul 5 23:01 TEST3
brw-rw----. 1 oracle dba 8, 36 Jul 5 23:01 TEST4
brw-rw----. 1 oracle dba 8, 17 Jul 5 23:01 OCR
brw-rw----. 1 oracle dba 8, 19 Jul 5 23:01 ACFS2
brw-rw----. 1 oracle dba 8, 18 Jul 5 23:01 ACFS1
brw-rw----. 1 oracle dba 8, 20 Jul 5 23:01 DATA
[root@oravb ~]#
CHECK FROM DB LEVEL :
SQL> select disk_number, header_status, mode_status, path, voting_file
from v$asm_disk; 2
DISK_NUMBER HEADER_STATU MODE_ST PATH V
----------- ------------ ------- ---------------------------------------- -
0 PROVISIONED ONLINE /dev/oracleasm/disks/TEST3 N
1 PROVISIONED ONLINE /dev/oracleasm/disks/TEST2 N
2 PROVISIONED ONLINE /dev/oracleasm/disks/TEST4 N
3 PROVISIONED ONLINE /dev/oracleasm/disks/TEST1 N
4. CREATE ASM DISKGREOUP :
CREATE DISKGROUP TEST EXTERNAL REDUNDANCY DISK '/dev/oracleasm/disks/TEST1';
Check if disk added or not :
SQL>col PATH for a40
set lines 150
set pages 100
col NAME for a20
col ASM_GROUP for a10
select adg.name ASM_GROUP, ad.disk_number, ad.name,ad.header_status, ad.mode_status,ad.REDUNDANCY, ad.path, ad.voting_file
from v$asm_diskgroup adg, v$asm_disk ad where adg.group_number = ad.group_number and adg.name='TEST' order by adg.name,ad.disk_number;
SQL> SQL> SQL> SQL> SQL> SQL> 2
ASM_GROUP DISK_NUMBER NAME HEADER_STATU MODE_ST REDUNDA PATH V
---------- ----------- -------------------- ------------ ------- ------- ---------------------------------------- -
TEST 0 TEST_0000 MEMBER ONLINE UNKNOWN /dev/oracleasm/disks/TEST1 N
5. Add disk on diskgroup :
Check the os disks state if it "PROVISIONED" then procced .
--where header_status = 'FORMER' order by disk_number; ---- which was the part of diskgroup
--where header_status = 'MEMBER' order by disk_number; -----wchich is the part of diskgroup currently uning
--where header_status = 'CANDIDATE' order by disk_number;---fresh disk
--where header_status = 'PROVISIONED' order by disk_number;----Disk is not part of a disk group and may be added to a disk group with the ALTER
SQL> ALTER DISKGROUP TEST ADD DISK '/dev/oracleasm/disks/TEST2';
Diskgroup altered.
SQL>
ASM_GROUP DISK_NUMBER NAME HEADER_STATU MODE_ST REDUNDA PATH V
---------- ----------- -------------------- ------------ ------- ------- ---------------------------------------- -
TEST 0 TEST_0000 MEMBER ONLINE UNKNOWN /dev/oracleasm/disks/TEST1 N
TEST 1 TEST_0001 MEMBER ONLINE UNKNOWN /dev/oracleasm/disks/TEST2 N
SQL>
6 . CHECK THE RBALCING STATE :
SQL> select operation, state,power, actual, sofar, est_work, est_minutes from v$asm_operation;
no rows selected
SQL>
CHANGE POWER LIMIT OF DISK :
SQL> ALTER DISKGROUP TEST REBALANCE POWER 4;
Diskgroup altered.
SQL> select operation, state,power, actual, sofar, est_work, est_minutes from v$asm_operation;
OPERA STAT POWER ACTUAL SOFAR EST_WORK EST_MINUTES
----- ---- ---------- ---------- ---------- ---------- -----------
REBAL REAP 4 4 0 0 0
REBAL DONE 4 4 0 0 0
REBAL DONE 4 4 0 0 0
SQL>
7 . DROP DISK FROM DISKGREOUP :
we can not drop disk on
SQL> ALTER DISKGROUP TEST DROP DISK 'TEST_0001' ;
SQL> ALTER DISKGROUP TEST DROP DISK 'TEST_0001' ;
Diskgroup altered.
SQL>
SQL> ^Ccol PATH for a40
set lines 150
set pages 100
col NAME for a20
col ASM_GROUP for a10
select adg.name ASM_GROUP, ad.disk_number, ad.name,ad.header_status, ad.mode_status,ad.REDUNDANCY, ad.path, ad.voting_file
from v$asm_diskgroup adg, v$asm_disk ad where adg.group_number = ad.group_number and adg.name='TEST' order by adg.name,ad.disk_number;
SQL> SQL> SQL> SQL> SQL> SQL> 2
ASM_GROUP DISK_NUMBER NAME HEADER_STATU MODE_ST REDUNDA PATH V
---------- ----------- -------------------- ------------ ------- ------- ---------------------------------------- -
TEST 0 TEST_0000 MEMBER ONLINE UNKNOWN /dev/oracleasm/disks/TEST1 N
TEST 2 TEST_0002 MEMBER ONLINE UNKNOWN /dev/oracleasm/disks/TEST3 N
TEST 3 TEST_0003 MEMBER ONLINE UNKNOWN /dev/oracleasm/disks/TEST4 N
SQL>
SQL> ALTER DISKGROUP TEST REBALANCE POWER 4;
Diskgroup altered.
SQL> select operation, state,power, actual, sofar, est_work, est_minutes from v$asm_operation;
OPERA STAT POWER ACTUAL SOFAR EST_WORK EST_MINUTES
----- ---- ---------- ---------- ---------- ---------- -----------
REBAL REAP 4 4 0 0 0
REBAL DONE 4 4 0 0 0
REBAL DONE 4 4 0 0 0
SQL>
Table 4-2 Mirroring options for Oracle ASM disk group types
| Disk Group Type | Supported Mirroring Levels | Default Mirroring Level |
|---|---|---|
External redundancy
|
Unprotected (none)
|
Unprotected
|
Normal redundancy
|
Two-way, three-way, unprotected (none)
|
Two-way
|
High redundancy
|
Three-way
|
Three-way
|
Flex redundancy
|
Two-way, three-way, unprotected (none)
|
Two-way (newly-created)
|
Extended redundancy
|
Two-way, three-way, unprotected (none)
|
Two-way
|
For normal and high disk group types, the redundancy level controls how many disk failures are tolerated without dismounting the disk group or losing data. Each file is allocated based on its own redundancy, but the default comes from the disk group.
For the flex group type, the number of failures tolerated before dismount demands on the number of failure groups. For five or more failure groups, two disk failures are tolerated. For three or four failure groups, one disk failure is tolerated.
For the extended disk group type, each site is similar to a flex disk group. If the site has five failure groups or more, two disk failures with in a site can be tolerated before the site becomes compromised. If the site has three or four failure groups, the site can tolerate one disk failure before the site is compromised. When two sites are compromised, the disk group dismounts. An extended disk group requires a minimum of three failure groups for each data site.
For flex and extended disk groups, mirroring describes the availability of the files within a disk group, not the disk group itself. For example: If a file is unprotected in a flex disk group that has five failure groups, then after one failure the disk group is still mounted, but the file becomes unavailable.
The redundancy levels are:
- External redundancyOracle ASM does not provide mirroring redundancy and relies on the storage system to provide RAID functionality. Any write error causes a forced dismount of the disk group. All disks must be located to successfully mount the disk group.
- Normal redundancyOracle ASM provides two-way mirroring by default, which means that all files are mirrored so that there are two copies of every extent. A loss of one Oracle ASM disk is tolerated. You can optionally choose three-way or unprotected mirroring.A file specified with
HIGHredundancy (three-way mirroring) in aNORMALredundancy disk group provides additional protection from a bad disk sector in one disk, plus the failure of another disk. However, this scenario does not protect against the failure of two disks. - High redundancyOracle ASM provides three-way (triple) mirroring by default. A loss of two Oracle ASM disks in different failure groups is tolerated.
- Flex redundancyOracle ASM provides two-way mirroring by default for newly-created flex disk groups. For migrated flex disk groups, the default values are obtained from the template values in the normal or high redundancy disk groups before migration. For migration from normal redundancy, if the template defaults were not changed, then the flex defaults are two-way mirroring. For migration from high redundancy, if the template defaults were not changed, then the flex defaults are three-way mirroring.
- Extended redundancyOracle ASM provides two-way mirroring by default. The redundancy setting describes redundancy within a data site. For example: If there is a two-way mirrored file in a two-data-site extended disk group, then there are four copies of the file, two in each data site.
Oracle ASM file groups in a flex or extended disk group can have different redundancy levels.
If there are not enough online failure groups to satisfy the file mirroring (redundancy attribute value) specified in the disk group file type template, Oracle ASM allocates as many mirrors copies as possible and subsequently allocates the remaining mirrors when sufficient online failure groups are available.
Failure groups enable the mirroring of metadata and user data. System reliability can diminish if your environment has an insufficient number of failure groups.
