ORA-00445: Background Process "xxxx" Did Not Start After 120 Seconds
Posted feiyun8616的作坊 (半个程序员and dba)
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了ORA-00445: Background Process "xxxx" Did Not Start After 120 Seconds相关的知识,希望对你有一定的参考价值。
Recent linux kernels have a feature called Address Space Layout Randomization (ASLR).
ASLR is a feature that is activated by default on some of the newer linux distributions.
It is designed to load shared memory objects in random addresses.
In Oracle, multiple processes map a shared memory object at the same address across the processes.
With ASLR turned on Oracle cannot guarantee the availability of this shared memory address.
This conflict in the address space means that a process trying to attach a shared memory object to a specific address may not be able to do so, resulting in a failure in shmat subroutine.
However, on subsequent retry (using a new process) the shared memory attachment may work.
The result is a "random" set of failures in the alert log.
SOLUTION
It should be noted that this problem has only been positively diagnosed in Redhat 5 and Oracle 11.2.0.2.
It is also likely, as per unpublished BUG:8527473, that this issue will reproduce running on Generic Linux platforms running any Oracle 11.2.0.x. or 12.1.0.x on Redhat/OEL kernels which have ASLR.
This issue has been seen in both Single Instance and RAC environments.
ASLR also exists in SLES10 and SLES 11 kernels and by default ASLR is turned on. To date no problem has been seen on SuSE servers running Oracle but Novell confirm ASLR may cause problems. Please refer to
http://www.novell.com/support/kb/doc.php?id=7004855 mmap occasionally infringes on stack
# /sbin/sysctl -a | grep randomize
kernel.randomize_va_space = 1
If the parameter is set to any value other than 0 then ASLR is in use.
On Redhat 5 to permanently disable ASLR.
add/modify this parameter in /etc/sysctl.conf
kernel.randomize_va_space=0
kernel.exec-shield=0
You need to reboot for kernel.exec-shield parameter to take effect.
Note that both kernel parameters are required for ASLR to be switched off.
以上是关于ORA-00445: Background Process "xxxx" Did Not Start After 120 Seconds的主要内容,如果未能解决你的问题,请参考以下文章