A Oracle Database Appliance Software Configuration Defaults

Oracle Database Appliance software configuration defaults.

Topics:

Directory Paths for Oracle Database Appliance

Oracle homes on Oracle Database Appliance follow Optimal Flexible Architecture guidelines.

Table A-1 Directory Paths for Oracle Database Appliance

Item Directory Path

Grid home

/u01/app/release-specific_name/grid

Grid base

/u01/app/grid

Oracle home

/u01/app/oracle/product/dbhome_release-specific_namesequence_number

Oracle base

/u01/app/oracle

Oracle Inventory

/u01/app/oraInventory

Oracle Groups and Users Configuration for Oracle Database Appliance

Review the table to see the groups and default users created when you deploy the appliance. All passwords are set to the Master password that you define during deployment.

Oracle Groups and Users Configurations

Table A-2 Oracle Groups and Users Configuration for Oracle Database Appliance

Groups and Users Default Value

Oracle Grid Infrastructure installation owner

grid, UID 1001

Oracle Database installation owner

oracle, UID 1000

Oracle Database system administrator

sys

Oracle Database generic administrator

system

Oracle Inventory system privileges group

oinstall, GID 1001

Oracle ASM Administrators system privileges

asmadmin, GID 1004

Oracle ASM Users system privileges

asmdba, GID 1006

Oracle ASM Operator system privileges

asmoper, GID 1005

Oracle Database Administrators system privileges

dba, GID 1003

Oracle Database Operator system privileges

dbaoper, GID 1002

System Configuration for Oracle Database Appliance

Review to see the configuration options for Oracle Database Appliance.

Table A-3 System Configuration for Oracle Database Appliance

Item Value

Oracle Linux with the Red Hat-compatible kernel

Oracle Linux 6.8 with kernel-4.1.12-61.44.1.el6uek.x86_64

Oracle Database release

12.1.0.2.170418, 11.2.0.4.170418

Oracle Database Enterprise Edition, Oracle Database Standard Edition 2, Oracle Database Standard Edition 1, Oracle Database Standard Edition

SCAN port number

1521

Oracle Enterprise Edition DB control port

1158

To access Enterprise Manager , enter the following URL string, where hostname is the name of one of the Oracle Database Appliance server nodes:

https://hostname:1158/em

Tuning IOps Values for Improved Performance with Expanded Memory

After you expand memory, tune the I/O per second (IOps) values by adjusting the values for kernel.sem, hugepage size, and oracle memlock limit to improve storage performance.

Performance is determined by the configuration of a fully deployed Oracle Database Appliance. After you expand the memory, use the oakcli reconfigure osparams command to view the current configuration and suggested values for memlock and vm.nr_hugepages. The values provided for tuning the kernel.sem, hugepage size, and oracle memlock are estimated values. Your settings might vary, depending on the workload.

Note:

When adjusting the settings, ensure that you make the changes on both nodes.

Increasing the kernel.sem Parameter

When running multiple Oracle databases on Oracle Database Appliance, increase the semaphore parameters (kernel.sem) on both nodes to improve performance.

The following semaphore parameters define shared memory:

  • semmsl:  The number of semaphores per set. The default is usually 250.

  • semmns:  The total number of semaphores available. The default is usually 32000.

  • semopm:  The number of operations which can be made per semaphore call. The default is usually 100.

  • semmni:  The maximum number of shared memory segments available in the system. The default is usually 142.

The parameters appear in order in the /etc/sysctl.conf file. For example, kernel.sem = 250 32000 100 142

Edit the values in the /etc/sysctl.conf file from 250 32000 100 142 to 1510 214420 1510 200on both nodes as follows:

# vi /etc/sysctl.conf 
kernel.sem=1510 214420 1510 200 
# sysctl -p /etc/sysctl.conf

Increasing the Size of HugePages

Using very large page sizes (greater than the default 4 KB) can improve system performance by reducing the amount of system resources required to access page table entries. With HugePages, the operating system page table (virtual memory to physical memory mapping) is smaller, since each page table entry is pointing to larger pages and the kernel has fewer pages whose lifecyle must be monitored.

Increase the hugepages from 67200 to 103865 on both nodes:

# vi /etc/sysctl.conf vm.nr_hugepages=103865 # sysctl -p /etc/sysctl.conf

Increasing the Memory Limits for the Oracle User

The memory limits for user oracleare calculated by multiplying the number of HugePages with the Hugepagesize. For example, 2013*2048 = 4122624.

Increase the memlock limit from 192000000 to 256000000 on both nodes:

# vi /etc/security/limits.conf
oracle  soft   memlock   256000000 
oracle   hard   memlock   256000000

Shared Memory Settings

The following parameters determine how much shared memory (in pages) is available to use:

  • shmall:  The total amount of shared memory that can be allocated on the system.

  • shmmax:  The maximum size of a shared memory segment.

  • shmmni:  The maximum number of shared memory segments available on the system. Oracle recommends 4096.

The current setting fully covers all the memory combinations.

total_mem = `cat /proc/meminfo | grep MemTotal: | awk '{print $2}`

For Huge pages =  (total_mem / 4096 ) * 1.05  (an extra 5% is added to handle any other processes, such as oc4j )

For memlock =  3/4 * total_mem

Estimated IOps Configuration for Performance with Expanded Memory

The table provides suggested configuration settings to improve performance after expanding memory. Adjust the settings on both nodes.

Table A-4 Oracle Database Appliance IOps Configuration Settings

Environment Variable 384 GB 512 GB 768 GB

memlock for oracle user

294000000

391000000

588000000

hugepages

102681

137088

205900

Note:

The memlock and hugepages settings are specified in KB.

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