Installation guide

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By enabling huge pages it will eliminate this page table problem. The same example 800GB SGA with 1024 users
now only requires 32GB for page tables. Even with thousands of users, HUGE pages keep the page tables
manageable.
To make sure Oracle 11gR2 database can use Huge Pages in Red Hat Enterprise Linux 5, you also need to increase
the ulimit parameter “memlock” for the oracle user in /etc/security/limits.conf unlimited.
To enable a 700GB SGA with HUGE pages, you will need to set the following parameters:
Table 10. Example of Linux and Oracle parameter settings for a 700GB Oracle SGA using HUGE pages
Init.ora
/etc/security/limits.conf
memory_target=0
sga_target = 0
sga_max_size= 740881858560
pga_aggregate_target = 200G
statistics_level = typical
use_large_pages = only
oracle soft memlock unlimited
oracle hard memlock unlimited
/etc/sysctl.conf
grep –i huge /proc/meminfo
vm.nr_hugepages = 358500 #2M pages
kernel.shmmax = 751828992000 #bytes
kernel.shmall = 183552000 #4K pages
HugePages_Total: 358500
HugePages_Free: 55508
HugePages_Rsvd: 50545
HugePages_Surp: 0
Hugepagesize: 2048 kB
Setting up Device-Mapper Multipathing
Device-Mapper (DM) Multipath was used to enable the DL980 to route I/O over the multiple paths available to all the
P2000 arrays. For P2000 arrays, HP is supporting DM Multipath which is bundled with the RHEL OS distribution or
patch release. A path refers to the physical connection from an HBA port to the P2000 storage controller port. We
used active/passive rather than load balancing or round robin multipathing options. Active/passive approach
provided the best overall performance. When load balancing was tested the performance of the I/O throughput
dropped significantly and we experienced higher I/O penalties. Please see Appendix 3 for an example of the
multipath.conf file used in this test configuration.
With active/passive whenever an active path through which I/O happens fails, DM Multipath reroutes the I/O over
other available paths. It provides transparent failover and failback of I/Os by rerouting I/Os automatically to this
alternative path when a path failure is sensed, and routing them back when the path has been restored. For Linux on
the DL980, when there are multiple paths to a storage controller, each path appears as a separate block device and
hence results in multiple block devices for a single LUN. DM Multipath creates a new Multipath block device for those
devices that have the same LUN WWN. Please refer to the Red Hat Enterprise Linux 5 DM Multipath configuration
guide and the Native Linux Multipath Disk Arrays Device-Mapper for HP StorageWorks reference guide for more
information on implementing multipathing (requires an HP Passport account).
Oracle Database configuration details
A standard installation of Oracle Database 11gR2 was performed on top of a standard installation of Red Hat
Enterprise Linux 5.7. This white paper does not cover installation of the Oracle 11gR2 database. Anything specific
from the engineering testing for this data warehouse reference architecture will be discussed.
For installing Oracle 11gR2 database please reference the following documents:
 Oracle Database Release Notes 11g Release 2 (11.2) for Linux
 Oracle Database Installation Guide 11g Release 2 (11.2) for Linux
 Oracle Database Quick Installation Guide 11g Release 2 (11.2) for Linux x86-64