ORA-27102: out of memory 故障

最新推荐文章于 2023-01-05 13:12:10 发布

congjiong8459

最新推荐文章于 2023-01-05 13:12:10 发布

阅读量271

点赞数

文章标签：数据库操作系统

今天在修改sga和pga参数后在启动DB ，遇到了ORA-27102 out of memory 故障，以下是产生该故障操作，增加了

点击(此处)折叠或打开

SQL> show parameter db_writer_processes;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_writer_processes integer 6
SQL> show parameter memory_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
memory_target big integer 57984M
SQL> show parameter sga_max_size
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
sga_max_size big integer 57984M
SQL> show parameter sga_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
sga_target big integer 0
SQL> show parameter pga_aggregate_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_target big integer 0
SQL> show parameter optimizer_mode
SQL> show parameter open_cursors
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
open_cursors integer 300
SQL> show parameter db_writer_processes
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_writer_processes integer 6
SQL>
SQL>
SQL>
SQL> alter system set memory_target=0 scope=spfile;
System altered.
SQL> alter system set sga_target=57984M scope=spfile;
System altered.
SQL> alter system set pga_aggregate_target=20480M scope=spfile;
System altered.
SQL> ALTER SYSTEM SET open_cursors=1000 scope=both;
System altered.
SQL>
SQL> startup force
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
Additional information: -134217728
Additional information: 1

好的，让我们来查下资料，这个out of memory 是如何

[ID 301830.1]

Upon startup of Linux database get ORA-27102: out of memory Linux-X86_64 Error: 28: No space left on device [ID 301830.1] To Bottom
--------------------------------------------------------------------------------
Modified:Oct 4, 2012Type:PROBLEMStatus:PUBLISHEDPriority:3 Comments (0)

In this Document
Symptoms
Ask Questions, Get Help, And Share Your Experiences With This Article
Changes
Cause
Solution
References
--------------------------------------------------------------------------------
Applies to:
Oracle Server - Standard Edition - Version 9.2.0.1 and later
Oracle Server - Enterprise Edition - Version 9.2.0.1 and later
Linux x86-64

Symptoms
When trying to increase the SGA to approach half available RAM with an Oracle 64-bit version on a Linux 64-bit operating system, even though shmmax is set to match half the amount of RAM, you get the following error when trying to start the instance:

SQL> startup nomount
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
Ask Questions, Get Help, And Share Your Experiences With This Article
Would you like to explore this topic further with other Oracle Customers, Oracle Employees, and Industry Experts?

Click here to join the discussion where you can ask questions, get help from others, and share your experiences with this specific article.
Discover discussions about other articles and helpful subjects by clicking here to access the main My Oracle Support Community page for Database Install/Upgrade.

Changes

shmall is too small, most likely is set to the default setting of 2097152

$ cat /proc/sys/kernel/shmall
2097152

Cause

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

Solution

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

NOTE:

The above command loads the new value and a reboot is not necessary.
Switch back to being the oracle user and retry the startup command.
Modifying /etc/sysctl.conf is a permanent workaround (applies at boot time). If for some reason you DO NOT want to change the system wide configuration, you can do it on the fly by directly changing the kernel pseudo FS AKA procfs.

e.g. echo "4194304" > /proc/sys/kernel/shmall

Using HUGEPAGES does not alter the calculation for configuring shmall.

所以，我们就来确定下操作系统层面的参数shmall 值，以及该参数的实际意义。

点击(此处)折叠或打开