oracle 19c RAC srvctl start database 启动数据库报错：

[oracle@ora19c-rac1 ~]$srvctl start database -d orcl
PRCR-1079 : Failed to start resource ora.orcl.db
CRS-5017: The resource action "ora.orcl.db start" encountered the following error:
ORA-00443: background process "LMD1" did not start
. For details refer to "(:CLSN00107:)" in "/u01/app/grid/diag/crs/ora19c-rac1/crs/trace/crsd_oraagent_oracle.trc".

CRS-2674: Start of 'ora.orcl.db' on 'ora19c-rac1' failed
CRS-2632: There are no more servers to try to place resource 'ora.orcl.db' on that would satisfy its placement policy
CRS-5017: The resource action "ora.orcl.db start" encountered the following error:
ORA-00443: background process "RBAL" did not start
. For details refer to "(:CLSN00107:)" in "/u01/app/grid/diag/crs/ora19c-rac2/crs/trace/crsd_oraagent_oracle.trc".

CRS-2674: Start of 'ora.orcl.db' on 'ora19c-rac2' failed

数据库alert日志报错：

Errors in file /u01/app/oracle/diag/rdbms/orcl/orcl1/trace/orcl1_psp0_42613.trc:
ORA-27300: OS system dependent operation:fork failed with status: 11
ORA-27301: OS failure message: Resource temporarily unavailable
ORA-27302: failure occurred at: skgpspawn5
2022-02-07T11:14:36.655060+08:00
Errors in file /u01/app/oracle/diag/rdbms/orcl/orcl1/trace/orcl1_lms1_42683_42689.trc (incident=64023):
ORA-00800: soft external error, arguments: [Set Priority Failed], [LMS1], [Check traces and OS configuration], [Check Oracle document and MOS notes], []
Incident details in: /u01/app/oracle/diag/rdbms/orcl/orcl1/incident/incdir_64023/orcl1_lms1_42683_42689_i64023.trc
2022-02-07T11:14:36.655931+08:00
Error attempting to elevate LMS1's priority: no further priority changes will be attempted for this process
LMS1 started with pid=25, OS id=42683_42689
2022-02-07T11:14:36.698538+08:00
Errors in file /u01/app/oracle/diag/rdbms/orcl/orcl1/trace/orcl1_lms0_42681_42688.trc (incident=64024):
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_64024/orcl1_lms0_42681_42688_i64024.trc
2022-02-07T11:14:36.699149+08:00

Error attempting to elevate LMS0's priority: no further priority changes will be attempted for this process
LMS0 started with pid=23, OS id=42681_42688
2022-02-07T11:14:37.625682+08:00
Process RMS0 died, see its trace file
USER (ospid: 42454): terminating the instance due to ORA error 443

此处有2点问题：

1：ORA-27300: OS system dependent operation:fork failed with status: 11

2：ORA-00800: soft external error, arguments: [Set Priority Failed], [LMS0], [Check traces and OS configuration], [Check Oracle document and MOS notes], []

问题1 根因：

DefaultTasksMax was set to default value(512).
systemd limited maximum number of tasks that may be created on the node.
This setting will also affect maxpid value on the OS.

解决办法：

vi /etc/systemd/system.conf

修改 DefaultTasksMax 值 为 infinity  （默认512，修改不限制）

重启操作系统

问题2根因：

Bug 28831618 : FAILED TO ELEVATE VKTM'S PRIORITY IN AIX WITH EVENT 10795 SET

解决办法：

cd $ORACLE_HOME/bin （oracle db home）root用户修改

chown root oradism

chmod u+s oradism