Database Reference
In-Depth Information
In addition to the two benefits mentioned previously, with ASMLib, it is possible to add a data protection feature
in the Linux kernel that will allow the checksum operation of a data block. This checksum will be validated at the
firmware level of the storage adapter before the data is sent to the storage network, where it is validated again at the
other end of the storage network before writing the data block to the physical disk. Wim Coekaerts's ASMLib blog at
https://blogs.oracle.com/wim/entry/asmLib
explains this new feature, which has its first implemention through
a joint effort by EMC, Emulex, and Oracle. For the details of this solution and its implementation, refer to the article
“How to Prevent Silent Data Corruption” at this link:
www.oracle.com/technetwork/articles/servers-storage-
Download and Install ASMLib Packages
ASMLib configuration starts with ASMLib package installation. All ASMLib installations require three rpms packages
installed on the host:
•
Support package: oracleasm-support
•
Tool library: oracleasmlib
•
Kernel driver: oracleasm
For Oracle Linux 5.x and Red Hat Enterprise Linux 5.x, you can download the rpms of these packages from
www.oracle.com/technetwork/server-storage/linux/downloads/rhel5-084877.html
and install them with the
rpm tool. For example, in Oracle Linux 5.8:
#rpm -ivh oracleasm-support-2.1.7-1.el5.x86_64.rpm
#rpm -ivh oracleasm-2.6.18-274.el5-2.0.5-1.el5.x86_64.rpm
#rpm -ivh oracleasmlib-2.0.4-1.el5.x86_64.rpm
The stories for Oracle Linux 6.x and Red Hat Enterprise Linux 6.x are different. Oracle ships Oracle Enterprise
Linux 6.x with two sets of kernel: Unbreakable Enterprise Kernel (UEK kernel), and Red Hat Compatible Kernel. You
can boot up your operating system with either of these kernels. For either of these two kernels, you need to download
the oracleasm-support from the Oracle Unbreakable Linux Network (ULN) (
https://linux.oracle.com/
)
if you have
an active support subscription or from the Oracle public Yum repository (
http://public-yum.oracle.com
)
. You also
need to download oracleasmlib from the Oracle ASMLib 2.0 web site:
http://www.oracle.com/technetwork/server-
However, for the oracleasm kernel driver, you will need to treat these two kernels differently. Since the oracleasm
kernel driver is already built into the UEK kernel, you don't need to load the oracleasm kernel driver if you boot up
your OS using the UEK kernel. If you use Oracle Linux 6.x Red Hat Campatible kernel, you need to download the
Oracleasm kernel driver kmod-oracleasm-2.0.6.rh1-2.el6.x86_64.rpm manually from ULN and install it:
rpm -ivh kmod-oracleasm-2.0.6.rh1-2.el6.x86_64.rpm
# yum install kmod-oracleasm
This kernel driver is not version-specific, and you don't need to upgrade the driver when the kernel is upgraded.
However, in order to install this rpm package, you need to run Oracle Linux Server release 6.4 and later with kernel
version > 2.6.32-358.el6. Otherwise, you will get an error message similar to this one, where the OS version is Oracle
Linux Server release 6.2:
[root]# rpm -ivh kmod-oracleasm-2.0.6.rh1-2.el6.x86_64.rpm
error: Failed dependencies:
kernel >= 2.6.32-358.el6 is needed by kmod-oracleasm-2.0.6.rh1-2.el6.x86_64
kernel(kmem_cache_alloc_trace) = 0x2044fa9e is needed by kmod-oracleasm-2.0.6.rh1-2.el6.x86_64
