Skip to main content

ABOUT HUGE PAGES FOR ORACLE ADMINS

HUGE PAGES:

 
Overview of HugePages
 

## HugePages is a feature integrated into the Linux kernel 2.6. Enabling HugePages makes it possible for the operating system to support memory pages greater than the default (usually 4 KB).

## Using very large page sizes can improve system performance by reducing the number of system resources required to access page table entries.

## Huge Pages is useful for both 32-bit and 64-bit configurations.

## Huge Page sizes vary from 2 MB to 256 MB, depending on the kernel version and the hardware architecture.


## For Oracle Databases, using Huge Pages reduces the operating system maintenance of page states, and increases Translation Lookaside Buffer (TLB) hit ratio.

 
the command to get Hugepagesize from os prompt

1) grep Hugepagesize /proc/meminfo

Hugepagesize:       2048 kB


2) grep Huge /proc/meminfo

AnonHugePages:         0 kB

HugePages_Total:   14016

HugePages_Free:     6639

HugePages_Rsvd:     6613

HugePages_Surp:        0

Hugepagesize:       2048 kB

Transparent HugePages memory differs from standard HugePages memory because the kernel khugepaged thread allocates memory dynamically during runtime. Standard HugePages memory is pre-allocated at startup, and does not change during runtime.

Comments

Popular posts from this blog

ORA-39014: One or more workers have prematurely exited.ORA-00018: maximum number of sessions exceeded

ERROR: I was Performing a full database import and during the import I faced the below error. ORA-39014: One or more workers have prematurely exited. ORA-39029: worker 6 with process name "DW07" prematurely terminated ORA-31672: Worker process DW07 died unexpectedly. Job "SYSTEM"."SYS_IMPORT_FULL_04" stopped due to fatal error at 00:59:40 ORA-39014: One or more workers have prematurely exited. SOLUTION:  Run the import with fewer parallel processes, like PARALLEL=2 instead of 8. I was able to run the import successfully. NOTE 1: This errors occurs when there are less session allocation in the database. check the session,process parameters and increase them accordingly. To avoid such errors again. NOTE 2 : Note: Increasing processes parameter increases the amount of shared memory that needs to be reserved & the OS must be configured to support the larger amount of shared memory. So here we first need to increase the Memory & SG...

ORA-01143: cannot disable media recovery - file 1 needs media recovery

I got a request from the client - To flashback the database to the existing restore point & disable flashback and archive log mode for database UATB. Here I came a cross error - ORA-01143. I followed the below steps. 1. SQL> select name from v$database; NAME ------------ UATB 2. SQL> SELECT NAME FROM V$RESTORE_POINT WHERE GUARANTEE_FLASHBACK_DATABASE='YES' ORDER BY TIME; NAME --------- UATB_COPY Here I'm going to restore the database to the above restore point. NOTE: The flashback database restore has to be done in MOUNT stage of the database. SQL> select name from v$database; NAME --------- UATB SQL> shut immediate; Database closed. Database dismounted. ORACLE instance shut down. SQL> startup mount ORACLE instance started. Total System Global Area  612368384 bytes Fixed Size                  1250428 bytes Variable Size             167775108 bytes ...