oracel 密码延时特性；更改 pfile导致启动报错ORA-49601: syntax error: found "%s": expecting one of: "%s" etc

[oracle@db ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.4.0 Production on Wed Dec 26 13:04:11 2018

Copyright (c) 1982, 2013, Oracle. All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> alter system set event ="28401 TRACE NAMECONTEXT FOREVER, LEVEL 1" scope=spfile; 之前是写错了
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORA-49601: syntax error: found "%s": expecting one of: "%s" etc..

SQL> create pfile='/home/oracle/a.txt' from spfile;

File created.
vi /home/oracle/a.txt #注销修改的参数
SQL> startup pfile='/home/oracle/a.txt';
ORACLE instance started.
Total System Global Area 2.0243E+10 bytes
Fixed Size 2261968 bytes
Variable Size 3758099504 bytes
Database Buffers 1.6442E+10 bytes
Redo Buffers 41164800 bytes
Database mounted.
Database opened.
alter system set event ="28401 TRACE NAME CONTEXT FOREVER, LEVEL 1" scope=spfile;
SQL> create spfile from pfile='/home/oracle/a.txt';

File created.

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

 ##监听链接状态有拒绝连接次数

[oracle@db ~]$ lsnrctl service

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 26-DEC-2018 12:50:34

Copyright (c) 1991, 2013, Oracle. All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=JHdb)(PORT=1521)))
Services Summary...
Service "orcl" has 1 instance(s).
Instance "orcl", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:68 refused:0 state:ready
LOCAL SERVER
Service "orclXDB" has 1 instance(s).
Instance "orcl", status READY, has 1 handler(s) for this service...
Handler(s):
"D000" established:0 refused:0 current:0 max:1022 state:ready
DISPATCHER <machine: JHdb, pid: 25543>
(ADDRESS=(PROTOCOL=tcp)(HOST=JHdb)(PORT=28940))
The command completed successfully