After OS installation and Configuration. We will configure and prepare a set of raw disks for OCFS2 (/dev/sdb), Oracle ASM (/dev/sdd, /dev/sde).

Log In as a root user on RAC1 and execute following steps:

# fdisk /dev/sdb
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-512, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-512, default 512):
Using default value 512
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.

# fdisk /dev/sdc
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-391, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-391, default 391):
Using default value 391
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.

# fdisk /dev/sdd
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-391, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-391, default 391):
Using default value 391
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.

# fdisk /dev/sde
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-261, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-261, default 261):
Using default value 261
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.

# fdisk -l
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 910 7309543+ 83 Linux
/dev/sda2 911 1170 2088450 82 Linux swap
/dev/sda3 1171 2610 11566800 83 Linux
Disk /dev/sdb: 536 MB, 536870912 bytes
64 heads, 32 sectors/track, 512 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 512 524272 83 Linux
Disk /dev/sdc: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdc1 1 391 3140676 83 Linux
Disk /dev/sdd: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdd1 1 391 3140676 83 Linux
Disk /dev/sde: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sde1 1 261 2096451 83 Linux

Now we will Map raw devices for ASM disks.

The raw devices have to bind with the block devices each time a cluster node boots.

Add the following lines in /etc/sysconfig/rawdevices.

/etc/sysconfig/rawdevices
/dev/raw/raw1 /dev/sdc1
/dev/raw/raw2 /dev/sdd1
/dev/raw/raw3 /dev/sde1

To make the mapping effective immediately, execute the following commands as the root user:

# /sbin/service rawdevices restart

Assigning devices:
/dev/raw/raw1 --> /dev/sdc1
/dev/raw/raw1: bound to major 8, minor 33
/dev/raw/raw2 --> /dev/sdd1
/dev/raw/raw2: bound to major 8, minor 49
/dev/raw/raw3 --> /dev/sde1
/dev/raw/raw3: bound to major 8, minor 65
done

# chown oracle:dba /dev/raw/raw[1-3]

# chmod 660 /dev/raw/raw[1-3]

# ls -lat /dev/raw/raw*
crw-rw---- 1 oracle dba 162, 3 Nov 4 07:04 /dev/raw/raw3
crw-rw---- 1 oracle dba 162, 2 Nov 4 07:04 /dev/raw/raw2
crw-rw---- 1 oracle dba 162, 1 Nov 4 07:04 /dev/raw/raw1

As the oracle user, execute

rac1-> ln -sf /dev/raw/raw1 /u01/oradata/devdb/asmdisk1
rac1-> ln -sf /dev/raw/raw2 /u01/oradata/devdb/asmdisk2
rac1-> ln -sf /dev/raw/raw3 /u01/oradata/devdb/asmdisk3

Modify /etc/udev/permissions.d/50-udev.permissions.

Raw devices are remapped on boot. The ownership of the raw devices will change to the root user by default upon boot. ASM will have problem accessing the shared partitions if the ownership is not the oracle user. Comment the original line, “raw/*:root:disk:0660” in /etc/udev/permissions.d/50-udev.permissions and add a new line, “raw/*:oracle:dba:0660.”

/etc/udev/permissions.d/50-udev.permissions

# raw devices
ram*:root:disk:0660
#raw/*:root:disk:0660
raw/*:oracle:dba:0660