Ksvcreate:process (m000) creation failed

A test server database (Oracle database 10g Release 10.2.0.5.0-64bit Production) is suddenly inaccessible, check that the database is in suspend mode (hang mode), check the alarm log, and find " Ksvcreate:process (m000) creation failed "," kkjcre1p:unable to spawn jobq slave Process "error message. The following are the specific examples:

Sun Jan 09:56:05 CST 2016

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Current Log# 1 seq# 1729 mem# 0:/u01/oradata/scm2/redo01.log

Sun Jan 21:34:01 CST 2016

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Current Log# 2 seq# 1730 mem# 0:/u01/oradata/scm2/redo02.log

Mon Jan 09:06:00 CST 2016

Ksvcreate:process (m000) creation failed

Mon Jan 09:12:50 CST 2016

Warning:inbound Connection timed out (ORA-3136)

Mon Jan 09:37:13 CST 2016

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Current Log# 3 seq# 1731 mem# 0:/u01/oradata/scm2/redo03.log

Mon Jan 09:43:10 CST 2016

Process

Mon Jan 09:43:10 CST 2016

 in FILE/U01/APP/ORACLE/ADMIN/SCM2/BDUMP/SCM2_CJQ0_586.TRC:

At that time the developer was anxious to test, did not have the time to study the specific reason, therefore restarted the database instance (cannot be closed through shutdown immeidate, only through the shutdown abort closes).

Regarding the error message in the alarm log, we see that the m000 process creation failed and the Pmon process could not start the process. In general, Pmon cannot start the process for some of the following reasons:

1. The number of Oracle connections exceeds the number of process limits. (It is because Oracle has reached the limit of the number of processes that Pmon cannot create the m000 process)

2. Deadlock of process.

Bug 8426816 Pmon Cleaning up a dead process (rare)

3, the bug caused by

Database hangs with Message ' ksvcreate:process (M001) Creation Failed ' (document ID 1233079.1)

After I checked the v$resource_limit, I found that the number of session connections and the number of processes was not super. Then it is entirely possible to exclude this factor, and now it could be a process deadlock or a bug.

Colleagues in the inspection process found that physic memory resources are seriously inadequate, causing the swap to read and write frequently. Continue to check the SGA parameter found Sga_max_size, sga_target settings too large (this test server is a virtual machine cloning, production environment of RAM for 64G,SGA also set large, after cloning Oracle instance can not boot, adjusted the Sga_target, Sga_max_size and other parameters to start the success, but I do not know why Sga_max_size set up to 11264M (11G), it is possible to set to 1G more, because the physical memory 3G more, but I do not know is the hand shook or dizzy, of course, do not rule out the back by people to get rid of, Actually set into a 11264M size, shame AH. Actually run so long until recently problems, test database basically do not do patrol)

Then in troubleshooting Guide (TSG)-ksvcreate:process (xxxx) Creation failed/ora-00445:background Process "xxxx" does not S Tart after n Seconds (document ID 1379200.1) found that when the resources or settings of the OS are incorrect, especially when physical memory or swap is insufficient, a new process cannot be generated. The English text is as follows:

OS Configuration Checks

This error is observed due to lack of OS resources or incorrect configuration, typically memory or swaps may Insuffi Cient to spawn a new process. Check the list below to verify the OS settings and configuration

Of course, I have some controversy with my colleagues about this. But I think these are the problems that caused the database to appear. Modifying the SGA-related parameters should solve this problem, but it will take a while to observe.

In addition, about the kswapd0 process, in the blog to adjust the Linux kernel as far as possible with memory, instead of swap inside there are more detailed introduction, excerpt part of the content as follows:

Linux uses KSWAPD for virtual memory management such, pages that havebeen recently accessed is kept in memory and Les s active pages is paged Outto disk.

(What is a page?) ... Linux uses manages memory in units called pages.

So,the KSWAPD process regularly decreases the ages of unreferencedpages...and at the end they is paged out (moved off) to Di Sk

The role of the KSWAPD0 process: It is the virtual memory management, responsible for changing the page, the operating system will wake up every certain time kswapd, to see if the memory is tense, if not tense, then sleep, in KSWAPD, there are 2 thresholds, pages_hige and Pages_low, When the number of free memory pages is less than Pages_low, the KSWAPD process scans the memory and releases 32 free pages at a time, until the number of the zero page reaches Pages_high.

Physical MEM is insufficient to cause swap to read and write frequently. KSWAPD0 is the system's virtual memory management program, if the physical memory is not enough, the system will wake up the kswapd0 process, the kswapd0 allocated disk swap space for caching, thus consuming a lot of CPU resources.

References:

http://www.myjishu.com/?p=80

http://www.nowamagic.net/librarys/veda/detail/2539

Ksvcreate:process (m000) creation failed