在Oracle21c之后，一些目录发生了变化，如监听配置文件、dbs目录。 示例如下：

Oracle21c安装之后，目录如下

1. #$ORACLE_BASE目录下
2. admin audit cfgtoollogs dbs diag homes oradata product
3. [oracle@oracle21 oracle]$ pwd
4. /u01/app/oracle
5. # 19c $ORACLE_BASE目录下。ASM
6. [oracle@rac19c oracle]$ ls
7. admin audit cfgtoollogs checkpoints diag product
9. #检查Oracle21c目录
10. [oracle@oracle21 oracle]$ orabasehome
11. /u01/app/oracle/homes/OraDB21Home1
12. [oracle@oracle21 oracle]$ orabaseconfig
13. /u01/app/oracle
14. [oracle@oracle21 oracle]$
15. #检查19c目录
16. [oracle@rac19c ~]$ orabasehome
17. /u02/app/oracle/product/19.0.0/db_1
18. [oracle@rac19c ~]$ orabaseconfig
19. /u02/app/oracle/product/19.0.0/db_1
20. [oracle@rac19c ~]$ orabase
21. /u02/app/oracle
22. [oracle@rac19c ~]$
24. #检查21c监听状态及文件位置,如下所示，已经在/homes/OraDB21Home1/network/admin/listener.ora目录下，配置tnsnames也需要在该目录下
25. [oracle@oracle21 oracle]$ lsnrctl stat
27. LSNRCTL for Linux: Version 21.0.0.0.0 - Production on 20-AUG-2021 13:52:09
29. Copyright (c) 1991, 2021, Oracle. All rights reserved.
31. Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=oracle21)(PORT=1521)))
32. STATUS of the LISTENER
33. ------------------------
34. Alias LISTENER
35. Version TNSLSNR for Linux: Version 21.0.0.0.0 - Production
36. Start Date 20-AUG-2021 13:33:24
37. Uptime 0 days 0 hr. 18 min. 45 sec
38. Trace Level off
39. Security ON: Local OS Authentication
40. SNMP OFF
41. Listener Parameter File /u01/app/oracle/homes/OraDB21Home1/network/admin/listener.ora
42. Listener Log File /u01/app/oracle/diag/tnslsnr/oracle21/listener/alert/log.xml
43. Listening Endpoints Summary...
44. (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=oracle21)(PORT=1521)))
45. (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
46. Services Summary...
47. Service "c8209f27c6b16005e053362ee80ae60e" has 1 instance(s).
48. Instance "mydb21", status READY, has 1 handler(s) for this service...
49. Service "c9e6ddb27463ad21e0531550a8c0a46d" has 1 instance(s).
50. Instance "mydb21", status READY, has 1 handler(s) for this service...
51. Service "mydb21" has 1 instance(s).
52. Instance "mydb21", status READY, has 1 handler(s) for this service...
53. Service "mydb21XDB" has 1 instance(s).
54. Instance "mydb21", status READY, has 1 handler(s) for this service...
55. Service "mypdb21" has 1 instance(s).
56. Instance "mydb21", status READY, has 1 handler(s) for this service...
57. The command completed successfully
58. [oracle@oracle21 oracle]$

检查数据库中一些信息

1. --检查spfile文件,已不在原来的ORACLE_HOME目录下
2. SQL> show parameter spfile
4. NAME TYPE VALUE
5. ------------------------------------ ----------- ------------------------------
6. spfile string /u01/app/oracle/dbs/spfilemydb21.ora
7. SQL>

虽然Oracle21c中想变化为只读目录，但目前查看目录权限，仍然可写。 权限如下：

1. SQL> Disconnected from Oracle Database 21c Enterprise Edition Release 21.0.0.0.0 - Production
2. Version 21.3.0.0.0
3. [oracle@oracle21 oracle]$ pwd
4. /u01/app/oracle
5. [oracle@oracle21 oracle]$ ls -lrt
6. total 32
7. drwxr-xr-x. 3 oracle oinstall 4096 Aug 19 16:18 product
8. drwxrwxr-x. 23 oracle oinstall 4096 Aug 19 16:35 diag
9. drwxr-x---. 3 oracle oinstall 4096 Aug 19 16:35 homes
10. drwxr-x---. 5 oracle oinstall 4096 Aug 19 16:42 cfgtoollogs
11. drwxr-x---. 3 oracle oinstall 4096 Aug 19 16:53 admin
12. drwxr-x---. 3 oracle oinstall 4096 Aug 19 16:53 oradata
13. drwxr-x---. 3 oracle oinstall 4096 Aug 19 16:55 audit
14. drwxr-x---. 2 oracle oinstall 4096 Aug 20 13:53 dbs
15. [oracle@oracle21 oracle]$

目前Oracle21c已经将一些目录分离出来，权限管理可以越来越细化，更好保障数据库的安全，后续继续测试。