数据库版本：Oracle 19.7
操作系统：Red Hat Enterpise Linux Server release 7.9（Maipo）
问题描述：巡检时发现数据库日志中报ORA-00800: soft external error, arguments: [Set Priority Failed], [VKTM]
数据库alert信息：
...
Starting backgroup process VKTM
2022-11-22T10:17:07.033439+08:00
Errors in file /u01/app/oracle/diag/rdbms/cdbcrm/cdbcrm1/trace/cdbcrm1_vktm_370944.trc (incident=49)
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/cdbcrm/cdbcrm1/incident/incdir_49/cdbcrm1_vktm_370944_i49.trc
2022-11-22T10:17:07.0335265+08:00
Error attempting to elevate VKTM's priority:no further priority changes will be attempted for this proces
分析处理过程：
1、检查检查VKTM或LMS优先级相关隐藏参数
SQL> select a.ksppinm "Parameter",
b.ksppstvl "Session Value",
c.ksppstvl "Instance Value",
a.KSPPDESC "Describtion"
from x$ksppi a, x$ksppcv b, x$ksppsv c
where a.indx = b.indx and a.indx = c.indx
and a.ksppinm like '_%' and a.ksppinm like
'_highest_priority_process%';
VKTM”或LMS*没有设置优先级
2、设置隐藏参数
SQL> alter system set "_high_priority_processes"='VKTM' scope=spfile;
3、重启数据库，RAC 2个节点。
4、再次验证隐藏参数是否生效。
SQL> select a.ksppinm "Parameter",
b.ksppstvl "Session Value",
c.ksppstvl "Instance Value",
a.KSPPDESC "Describtion"
from x$ksppi a, x$ksppcv b, x$ksppsv c
where a.indx = b.indx and a.indx = c.indx
and a.ksppinm like '_%' and a.ksppinm like
'_highest_priority_process%';
[bjdb09:oracle]:/u01/app/oracle/product/19.7/db_1/bin>ls-l ora
-rwxr-xr-x l oracle oinstall 6153104 Apr 17 2019 orabase
-rwxr-x--- 1 oracle oinstall 1847960 Apr 17 2019 orabaseconfig
-rwxr-x--- 1 oracle oinstall 1847960 Apr 17 2019orabasehome
-rwxr-x--- l oracle oinstall 46 Nov 8 2000oracg
-rwsr-s--x 1 oracle asmadmin443249632 Sep26 2021 bracle
-rrwsr-x--- 1 root oinstall 147848 Apr 17 2019 oradism
-rwxr-xr-x 1 oracle oinstall 173040 Apr 11 2020 oradnfs
-rwxr-xr-x l oracle oinstall 2412 Sep 26 2021oradnfs run.sh
-rwxr-xr-x 1 oracle oinstall 6823 Jan 1 2000 oraenv·
-rwxr-x--- l oracle oinstall 44 Dec 5 2002 orajaxb
-rwxr-xr-x l oracle.oinstall 2790 Jan1 2000 orald
-rxr-x--- 1 oracle oinstall 54696 Apr 17 2019 oraping
-rwxr-x--- l oracle oinstall 59 Nov 26 2002 orapipe
-rxr-xr-x l oracle oinstall 4619 Na. 2 2029 orapki
-rxr-x--x l oracle oinstall 151392 Sep 26;2022 orapwd
oradism缺少s权限
使用root用户执行
# chmod u+s oradism
如果以上设置后，还存在问题，请检查PMON or VKTMs cpu cgroups相关设置
[bjdb09:oracle]ps -eaf|grep -i pmon|grep -v grep
[bjdb09:oracle]
cat /proc/6108449/cgroup | grep cpu
9:cpuset:/
7:cpuacct,cpu:/user.slice
如果cpuacct不是7，请在操作系统执行以下命名后再设置数据库隐藏参数_high_priority_processes
[bjdb09:root]
1. echo 0 > /sys/fs/cgroup/cpu,cpuacct/system.slice/cpu.rt_runtime_us
2. echo 950000 > /sys/fs/cgroup/cpu,cpuacct/user.slice/cpu.rt_runtime_us
-the end-
