ASM like RAID 1 between two storages

Question

In my production environment instances of Oracle are under the file system JFS2. Soon we will have to relocate space for these file or switch to ASM. Our preference is going to the ASM, but we do need some tests we are conducting.
Today, in a production environment, data from storage1 are replicated via AIX / HACMP for storage2.
Our tests with the ASM has to contemplate the use of a set of disks in storage1 and another set in storage2.
Below the details of the environment:
In AIX 5.3 TL8+
root@suorg06_BKP:/> lspv+
hdisk17 none None
hdisk18 none None
hdisk19 none None
hdisk16 none None
root@suorg06_BKP:/> fget_config -Av*
---dar0---
User array name = 'STCATORG01'
dac0 ACTIVE dac1 ACTIVE
Disk DAC LUN Logical Drive
hdisk17 dac0 15 ASMTST_02
hdisk16 dac0 14 ASMTST_01
---dar1---
User array name = 'STCATORG02'
dac4 ACTIVE dac5 ACTIVE
Disk DAC LUN Logical Drive
hdisk18 dac5 16 ASMTST_B01
hdisk19 dac5 17 ASMTST_B02
select+
*  lpad(name,15) as name,*
*  group_number,*
*  disk_number,*
*  mount_status,*
*  header_status,*
*  state,*
*  redundancy,*
*  lpad(path,15) as path,*
*  total_mb,*
*  free_mb,*
*  to_char(create_date,'dd/mm/yyyy') as create_date,*
*  to_char(mount_date,'dd/mm/yyyy') as mount_date*
from+
*  v$asm_disk*
order by+
*  disk_number;*
NAME GROUP_NUMBER DISK_NUMBER MOUNT_S HEADER_STATU STATE REDUNDA PATH TOTAL_MB FREE_MB
0 0 CLOSED CANDIDATE NORMAL UNKNOWN /dev/rhdisk16 30720 0
0 1 CLOSED CANDIDATE NORMAL UNKNOWN /dev/rhdisk17 30720 0
0 2 CLOSED CANDIDATE NORMAL UNKNOWN /dev/rhdisk18 30720 0
0 3 CLOSED CANDIDATE NORMAL UNKNOWN /dev/rhdisk19 30720 0
select+
*  v$asm_diskgroup.group_number,*
*  lpad(v$asm_diskgroup.name,20) as name,*
*  v$asm_diskgroup.sector_size,*
*  v$asm_diskgroup.block_size,*
*  v$asm_diskgroup.allocation_unit_size,*
*  v$asm_diskgroup.state,*
*  v$asm_diskgroup.type,*
*  v$asm_diskgroup.total_mb,*
*  v$asm_diskgroup.free_mb,*
*  v$asm_diskgroup.offline_disks,*
*  v$asm_diskgroup.unbalanced,*
*  v$asm_diskgroup.usable_file_mb*
from+
*  v$asm_diskgroup*
order by+
*  v$asm_diskgroup.group_number;*
no rows selected
SQL> CREATE DISKGROUP 'DB_DG_TESTE' NORMAL REDUNDANCY DISK '/dev/rhdisk16', '/dev/rhdisk18';+
Diskgroup created.
select+
*  lpad(name,15) as name,*
*  group_number,*
*  disk_number,*
*  mount_status,*
*  header_status,*
*  state,*
*  redundancy,*
*  lpad(path,15) as path,*
*  total_mb,*
*  free_mb,*
*  to_char(create_date,'dd/mm/yyyy') as create_date,*
*  to_char(mount_date,'dd/mm/yyyy') as mount_date*
from+
*  v$asm_disk*
order by+
*  disk_number;*
NAME GROUP_NUMBER DISK_NUMBER MOUNT_S HEADER_STATU STATE REDUNDA PATH TOTAL_MB FREE_MB CREATE_DAT MOUNT_DATE
DB_DG_TESTE_000 1 0 CACHED MEMBER NORMAL UNKNOWN /dev/rhdisk16 30720 30669 09/12/2008 09/12/2008
0 1 CLOSED CANDIDATE NORMAL UNKNOWN /dev/rhdisk17 30720 0 09/12/2008 09/12/2008
DB_DG_TESTE_000 1 1 CACHED MEMBER NORMAL UNKNOWN /dev/rhdisk18 30720 30669 09/12/2008 09/12/2008
0 3 CLOSED CANDIDATE NORMAL UNKNOWN /dev/rhdisk19 30720 0 09/12/2008 09/12/2008
select+
*  v$asm_diskgroup.group_number,*
*  lpad(v$asm_diskgroup.name,20) as name,*
*  v$asm_diskgroup.sector_size,*
*  v$asm_diskgroup.block_size,*
*  v$asm_diskgroup.allocation_unit_size,*
*  v$asm_diskgroup.state,*
*  v$asm_diskgroup.type,*
*  v$asm_diskgroup.total_mb,*
*  v$asm_diskgroup.free_mb,*
*  v$asm_diskgroup.offline_disks,*
*  v$asm_diskgroup.unbalanced,*
*  v$asm_diskgroup.usable_file_mb*
from+
*  v$asm_diskgroup*
order by+
*  v$asm_diskgroup.group_number;*
GROUP_NUMBER NAME SECTOR_SIZE BLOCK_SIZE ALLOCATION_UNIT_SIZE STATE TYPE TOTAL_MB FREE_MB OFFLINE_DISKS U USABLE_FILE_MB
1 DB_DG_TESTE 512 4096 1048576 MOUNTED NORMAL 61440 61338 0 N _30669_
SQL> ALTER DISKGROUP 'DB_DG_TESTE' ADD DISK '/dev/rhdisk17', '/dev/rhdisk19';+
select+
*  lpad(name,15) as name,*
*  group_number,*
*  disk_number,*
*  mount_status,*
*  header_status,*
*  state,*
*  redundancy,*
*  lpad(path,15) as path,*
*  total_mb,*
*  free_mb,*
*  to_char(create_date,'dd/mm/yyyy') as create_date,*
*  to_char(mount_date,'dd/mm/yyyy') as mount_date*
from+
*  v$asm_disk*
order by+
*  disk_number;*
NAME GROUP_NUMBER DISK_NUMBER MOUNT_S HEADER_STATU STATE REDUNDA PATH TOTAL_MB FREE_MB CREATE_DAT MOUNT_DATE
DB_DG_TESTE_000 1 0 CACHED MEMBER NORMAL UNKNOWN /dev/rhdisk16 30720 30681 09/12/2008 09/12/2008
DB_DG_TESTE_000 1 1 CACHED MEMBER NORMAL UNKNOWN /dev/rhdisk18 30720 30681 09/12/2008 09/12/2008
DB_DG_TESTE_000 1 2 CACHED MEMBER NORMAL UNKNOWN /dev/rhdisk17 30720 30682 09/12/2008 09/12/2008
DB_DG_TESTE_000 1 3 CACHED MEMBER NORMAL UNKNOWN /dev/rhdisk19 30720 30681 09/12/2008 09/12/2008
select+
*  v$asm_diskgroup.group_number,*
*  lpad(v$asm_diskgroup.name,20) as name,*
*  v$asm_diskgroup.sector_size,*
*  v$asm_diskgroup.block_size,*
*  v$asm_diskgroup.allocation_unit_size,*
*  v$asm_diskgroup.state,*
*  v$asm_diskgroup.type,*
*  v$asm_diskgroup.total_mb,*
*  v$asm_diskgroup.free_mb,*
*  v$asm_diskgroup.offline_disks,*
*  v$asm_diskgroup.unbalanced,*
*  v$asm_diskgroup.usable_file_mb*
from+
*  v$asm_diskgroup*
order by+
*  v$asm_diskgroup.group_number;*
GROUP_NUMBER NAME SECTOR_SIZE BLOCK_SIZE ALLOCATION_UNIT_SIZE STATE TYPE TOTAL_MB FREE_MB OFFLINE_DISKS U USABLE_FILE_MB
1 DB_DG_TESTE 512 4096 1048576 MOUNTED NORMAL 122880 122725 0 N 46002
At the end of the creation of diskgroup you can see the query that the space available for the diskgroup is 30669 MB, but after the addition of two other discs the size in MB available 46002.
It was not expected that the space available for use was approximately 50% of total discs?
How should I proceed with the creation of diskgroup to have it in the
mirror storage1 with storage2 without this great loss of space
Edited by: scarlosantos on Dec 9, 2008 4:39 PM

Answer 1

Maybe my phrasing was bad in the last post.
You can do the RAID on IDE 3 by creating the array with either SATA 1 or 2. To install the driver, you must bootup with your Windows CD and hit F6 when being prompt to install 3rd party Drivers for RAID/SCSI.
You should have the SATA driver Floppy disk with you and it is required to install the drivers.
After installing the drivers, exit Windows installation and reboot, during reboot press Ctrl F to enter the Promise RAID array menu and you are up to do the RAID. Please read through the Serial ATA Raid manual for more info.