Shulou(Shulou.com)06/01 Report--

I. Description

At present, more and more X86 servers are used in production environments, and non-core systems basically do not use minicomputers.

Client server expands memory, tries to modify SGA size, but prompts to report memory overflow. The original physical memory 8G, expansion to 32G, SGA and PGA need to be adjusted to play an optimized effect.

Second, the error information is as follows

SQL> startup nomount

ORA-27102: out of memory

Linux-x86_64 Error: 28: No space left on device

The first feeling seems to be that physical memory is not enough, we set SGA+PGA= about 60% of physical memory, the result is an error, here remind everyone, before modifying parameters, be sure to backup parameter files.

III. Analysis

We need to know that when installing the database, we actually modified a file/etc/sysctl.conf. The contents of this file should know what it means. Do not copy and paste. Here's why:

SHMALL is the total amount of shared memory, in pages, that the system can use at one time.

IV. Solutions

Set SHMALL equal to the sum of all the SGAs on the system, divided by the page size.

The page size can be determined using the following command:

$ getconf PAGE_SIZE

4096

For example, if the sum of all the SGAs on the system is 16Gb and the result of '$ getconf PAGE_SIZE' is 4096 (4Kb) then set shmall to 4194304 pages

As the root user set the SHMALL to 4194304 in the /etc/sysctl.conf file:

kernel.shmall = 4194304

then run the following command:

$ sysctl -p

$ cat /proc/sys/kernel/shmall

4194304

V. Summary

For students who don't know about/etc/sysctl.conf, they need to make up for it. Like friends can forward, welcome technical exchanges.

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