在一套19.14的linux 2节点rac库中,使用sqlplus启动数据库成功,但是alert日志中报ORA-00800: soft external error, arguments: [Set Priority Failed]错误.

2022-09-21T22:20:35.924251+08:00
Starting background process VKTM
2022-09-21T22:20:35.977936+08:00
Errors in file /u01/app/oracle/diag/rdbms/orcl/orcl1/trace/orcl1_vktm_22653.trc  (incident=880052):
ORA-00800: soft external error, arguments: [Set Priority Failed], [VKTM],
 [Check traces and OS configuration], [Check Oracle document and MOS notes], []
Incident details in: /u01/app/oracle/diag/rdbms/orcl/orcl1/incident/incdir_880052/orcl1_vktm_22653_i880052.trc
2022-09-21T22:20:35.980555+08:00
Error attempting to elevate VKTM's priority: no further priority changes will be attempted for this process
VKTM started with pid=6, OS id=22653

Starting background process LMHB
2022-09-21T22:20:36.467831+08:00
Errors in file /u01/app/oracle/diag/rdbms/orcl/orcl1/trace/orcl1_lms0_22703_22708.trc  (incident=920005):
ORA-00800: soft external error, arguments: [Set Priority Failed], [LMS0], 
[Check traces and OS configuration], [Check Oracle document and MOS notes], []
Incident details in: /u01/app/oracle/diag/rdbms/orcl/orcl1/incident/incdir_920005/orcl1_lms0_22703_22708_i920005.trc
2022-09-21T22:20:36.470535+08:00
Error attempting to elevate LMS0's priority: no further priority changes will be attempted for this process

错误提示比较明显,提升进程的优先级失败,通过操作系统命令观察发现确实进程优先级没有提升

[root@oradb01 ~]# ps -eo pid,class,pri,nice,time,args|grep vktm|grep -v grep 
 5656 TS   19   0 00:00:00 ora_vktm_orcl1
30838 RR   41   - 13:08:36 ora_vktm_+ASM1

重新使用srvctl启动数据库,优先级提升正常,alert日志中也无类似警告

[root@oradb01 ~]# ps -eo pid,class,pri,nice,time,args|grep vktm|grep -v grep 
 5716 RR   41   0 00:00:00 ora_vktm_orcl1
30838 RR   41   - 13:18:46 ora_vktm_+ASM1

这个问题一直困惑了很久,今天无意中在mos上发现了相关mos文档,具体参考:(DB50) Clusterware Fails to Start Because CSSD Cannot Get Real-Time Priority (Doc ID 2903663.1),由于 bug 34286265 and bug 34318125(Bug 34649727 Linux: ORA-800 / Set Priority / DB Performance Merge Patch for 19.17 – 34286265 34318125)

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尽量不要使用sqlplus去启动数据库,而是选择使用srvctl,避免在rac环境中导致数据库后台关键进程优先级无法提升问题.