Oracle ASMLib

This blog post is more of a note for myself on configuring ASMLib.

ASMLib is an optional utility that can be used on Linux systems to manage Oracle ASM devices.

ASMLib consists of the following components:

An open source (GPL) kernel module package: kmod-oracleasm
An open source (GPL) utilities package: oracleasm-support
A closed source (proprietary) library package: oracleasmlib

On my Oracle VMBox, I performed the below steps –

1. Check the installed packages related to oracleasm

[root@oel67-12c dev]# rpm -qa | grep oracleasm
[root@oel67-12c dev]#

2. As no rpm were installed, I started installing the packages

[root@oel67-12c dev]# yum install oracleasm-support
Loaded plugins: refresh-packagekit, security, ulninfo
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package oracleasm-support.x86_64 0:2.1.8-1.el6 will be installed
--> Finished Dependency Resolution
..........................
Installed:
  oracleasm-support.x86_64 0:2.1.8-1.el6

Complete!
[root@oel67-12c dev]#
[root@oel67-12c dev]# yum install kmod-oracleasm
Loaded plugins: refresh-packagekit, security, ulninfo
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package kmod-oracleasm.x86_64 0:2.0.8-13.el6_8 will be installed
--> Processing Dependency: kernel >= 2.6.32-642.el6 for package: kmod-oracleasm-2.0.8-13.el6_8.x86_64

...........................
Is this ok [y/N]: y
Downloading Packages:
(1/2): kernel-2.6.32-642.el6.x86_64.rpm
(2/2): kmod-oracleasm-2.0.8-13.el6_8.x86_64.rpm   

...........................

Installed:
  kmod-oracleasm.x86_64 0:2.0.8-13.el6_8

Dependency Installed:
  kernel.x86_64 0:2.6.32-642.el6

Complete!
[root@oel67-12c dev]#

3. Download the oracleasmlib rpm from http://www.oracle.com/technetwork/server-storage/linux/asmlib/rhel6-1940776.html and install it. Without this RPM, you will not have the oracleasm-discover executable


[root@oel67-12c dev]# ls -lrt /media/sf_12cR1/oracleasmlib*
-rwxrwx--- 1 root vboxsf    13336 May 18 21:44 oracleasmlib-2.0.12-1.el6.x86_64.rpm

[root@oel67-12c sf_12cR1]# rpm -ihv oracleasmlib-2.0.12-1.el6.x86_64.rpm
Preparing...                ########################################### [100%]
   1:oracleasmlib           ########################################### [100%]
[root@oel67-12c sf_12cR1]#

4. Verify all the components are installed

[root@oel67-12c sf_12cR1]# rpm -qa | grep oracleasm
oracleasm-support-2.1.8-1.el6.x86_64
oracleasmlib-2.0.12-1.el6.x86_64
kmod-oracleasm-2.0.8-13.el6_8.x86_64
[root@oel67-12c sf_12cR1]# cd 
[root@oel67-12c ~]# which oracleasm
/usr/sbin/oracleasm
[root@oel67-12c ~]#

5. Configure oracleasm — will configure the on-boot properties of the Oracle ASM library driver as well as set the appropriate file permissions.

[root@oel67-12c dev]# oracleasm configure -i
Configuring the Oracle ASM library driver.

This will configure the on-boot properties of the Oracle ASM library
driver.  The following questions will determine whether the driver is
loaded on boot and what permissions it will have.  The current values
will be shown in brackets ('[]').  Hitting  without typing an
answer will keep that current value.  Ctrl-C will abort.

Default user to own the driver interface []: oracle
Default group to own the driver interface []: oinstall
Start Oracle ASM library driver on boot (y/n) [n]: y
Scan for Oracle ASM disks on boot (y/n) [y]: y
Writing Oracle ASM library driver configuration: done
[root@oel67-12c dev]#

The configuration setting done above, can be checked in /etc/sysconfig/oracleasm

[root@oel67-12c dev]# ls -lrt /etc/sysconfig/oracleasm
lrwxrwxrwx 1 root root 24 May 18 22:02 /etc/sysconfig/oracleasm -> oracleasm-_dev_oracleasm

6. Check the status

[root@oel67-12c ~]# oracleasm status
Checking if ASM is loaded: no
Checking if /dev/oracleasm is mounted: no
[root@oel67-12c ~]#

7. Load oracleasm module with the init command

[root@oel67-12c ~]# oracleasm init
Creating /dev/oracleasm mount point: /dev/oracleasm
Loading module "oracleasm": oracleasm
Configuring "oracleasm" to use device physical block size
Mounting ASMlib driver filesystem: /dev/oracleasm
[root@oel67-12c ~]#

8. Verify the oracleasm configuration

a. Perform ‘df –ha’, this should show you that /dev/oracleasmfs is mounted.


[root@oel67-12c ~]# df -ha
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/vg_oel6712c-lv_root
                       45G  7.4G   36G  18% /
....................
oracleasmfs              0     0     0    - /dev/oracleasm

b. Execute the ‘lsmod’ command, to show the loaded oracleasm module.

[root@oel67-12c ~]# lsmod | grep oracleasm
Module                  Size  Used by
oracleasm              53591  1

9. Create the partition on disk , if not already done

[root@oel67-12c oracleasm]# lsblk
NAME                           MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                              8:0    0   50G  0 disk
├─sda1                           8:1    0  500M  0 part /boot
└─sda2                           8:2    0 49.5G  0 part
  ├─vg_oel6712c-lv_root (dm-0) 252:0    0 45.6G  0 lvm  /
  └─vg_oel6712c-lv_swap (dm-1) 252:1    0  3.9G  0 lvm  [SWAP]
sdb                              8:16   0   10G  0 disk
sdc                              8:32   0   12G  0 disk
sdd                              8:48   0   12G  0 disk
sde                              8:64   0   10G  0 disk
sdf                              8:80   0   12G  0 disk
sr0                             11:0    1 55.5M  0 rom  /media/VBOXADDITIONS_5.0.20_106931


[root@oel67-12c disks]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x50e6a869.
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):
Value out of range.
Partition number (1-4): 1
First cylinder (1-1305, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305):
Using default value 1305

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.
[root@oel67-12c disks]#
[root@oel67-12c disks]#
[root@oel67-12c disks]#
[root@oel67-12c disks]# lsblk
NAME                           MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                              8:0    0   50G  0 disk
├─sda1                           8:1    0  500M  0 part /boot
└─sda2                           8:2    0 49.5G  0 part
  ├─vg_oel6712c-lv_root (dm-0) 252:0    0 45.6G  0 lvm  /
  └─vg_oel6712c-lv_swap (dm-1) 252:1    0  3.9G  0 lvm  [SWAP]
sdb                              8:16   0   10G  0 disk
└─sdb1                           8:17   0   10G  0 part
sdc                              8:32   0   12G  0 disk
sdd                              8:48   0   12G  0 disk
sde                              8:64   0   10G  0 disk
sdf                              8:80   0   12G  0 disk
sr0                             11:0    1 55.5M  0 rom /media/VBOXADDITIONS_5.0.20_106931

Perform the same above steps for remaining disk.

10. Once the disk are created, label the disks as ASM disks and give then an ASM name.


[root@oel67-12c disks]# oracleasm createdisk data0101 /dev/sdb1
Writing disk header: done
Instantiating disk: done
[root@oel67-12c disks]# oracleasm createdisk data0102 /dev/sde1
Writing disk header: done
Instantiating disk: done
[root@oel67-12c disks]# ls -lrt
total 0
brw-rw---- 1 oracle oinstall 8, 17 May 18 22:49 DATA0101
brw-rw---- 1 oracle oinstall 8, 65 May 18 22:50 DATA0102

11. Check the configured disk using listdisks

[root@oel67-12c disks]# oracleasm listdisks
DATA0101

12. You can query the disk to check if its a valid ASM Disk

[root@oel67-12c disks]# oracleasm querydisk -d DATA0101
Disk "DATA0101" is a valid ASM disk on device [8,17]

[root@oel67-12c disks]# more /proc/partitions
major minor  #blocks  name
   8    17   10482381 sdb1

[root@oel67-12c sbin]# blkid|grep asm
/dev/sdb1: LABEL="DATA0101" TYPE="oracleasm"
/dev/sde1: LABEL="DATA0102" TYPE="oracleasm"
[root@oel67-12c sbin]#

The [8,17] is the major,minor number of the device with this partition. The value comes from /proc/partitions

major — The major number of the device with this partition. The major number in the /proc/partitions, (3), corresponds with the block device ide0, in /proc/devices.

minor — The minor number of the device with this partition. This serves to separate the partitions into different physical devices and relates to the number at the end of the name of the partition.

#blocks — Lists the number of physical disk blocks contained in a particular partition.

name — The name of the partition.

13. oracleasm-discover


[root@oel67-12c sbin]# oracleasm-discover
-bash: /usr/sbin/oracleasm-discover: /lib/ld-linux.so.2: bad ELF interpreter: No such file or directory

For the above error install/lib/ld-linux.so.2

[root@oel67-12c ~]# yum install /lib/ld-linux.so.2
Loaded plugins: refresh-packagekit, security, ulninfo
Setting up Install Process
public_ol6_latest/filelists                                                                                                                                                             |  61 MB     00:43
Resolving Dependencies
--> Running transaction check
---> Package glibc.i686 0:2.12-1.192.el6 will be installed
Dependencies Resolved

..................
Complete!
[root@oel67-12c ~]#

[root@oel67-12c ~]# ls -lrt /lib/ld-linux.so.2
lrwxrwxrwx 1 root root 10 May 18 23:25 /lib/ld-linux.so.2 -> ld-2.12.so
[root@oel67-12c ~]#
[root@oel67-12c ~]# oracleasm-discover
Using ASMLib from /opt/oracle/extapi/32/asm/orcl/1/libasm.so
[ASM Library - Generic Linux, version 2.0.4 (KABI_V2)]
Discovered disk: ORCL:DATA0101 [20964762 blocks (10733958144 bytes), maxio 512]
Discovered disk: ORCL:DATA0102 [20964762 blocks (10733958144 bytes), maxio 512]
[root@oel67-12c ~]#

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