Where is alert log when diagnostic_dest is not writable

David BudáčDavid Budáč
5 min read

The defaults

By default, the parameters look like this. Even though they're deprecated:

[oracle@ol9-19-dg1/cdb1 ~]# sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Thu Apr 3 16:20:30 2025
Version 19.22.0.0.0

Copyright (c) 1982, 2023, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.22.0.0.0

SQL> show parameter dump_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
background_dump_dest                 string      /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log
core_dump_dest                       string      /u01/app/oracle/diag/rdbms/cdb1/cdb1/cdump
user_dump_dest                       string      /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log

SQL> show parameter diagnostic_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
diagnostic_dest                      string      /u01/app/oracle

But if you try to set it manually, you'll get:

ORA-32004: obsolete or deprecated parameter(s) specified for RDBMS instance

Something in the instance IS writing traces here:

[oracle@ol9-19-dg1/cdb1 /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log]$ head -n 50 cdb1_ora_2793.trc
Dump file /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log/cdb1_ora_2793.trc
Build label:    RDBMS_19.22.0.0.0DBRU_LINUX.X64_231229
*** 2025-03-25T16:42:23.763390+00:00
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.22.0.0.0
Build label:    RDBMS_19.22.0.0.0DBRU_LINUX.X64_231229
ORACLE_HOME:    /u01/app/oracle/product/19.0.0/dbhome_1
System name:    Linux
Node name:      ol9-19-dg1.localdomain
Release:        5.15.0-301.163.5.2.el9uek.x86_64
Version:        #2 SMP Wed Oct 16 18:55:42 PDT 2024
Machine:        x86_64
Storage:        ?
CLID:   U
Instance name: cdb1
Redo thread mounted by this instance: 0 <none>
Oracle process number: 0
Unix process pid: 2793, image:


*** 2025-03-25T16:42:23.765333+00:00
 value for _ksi_trace_bucket SHARED2025-03-25 16:42:23.782 : kjbrpdnr: startup nress=0
2025-03-25 16:42:23.785 : kjblpdnl: startup nslocks=0
kgfmIsAppliance=0 (due to init)
KJHA:2phase 132 crs active
KJHA:2phase 210 usecnt:0 tha start prepare
2025-03-25 16:42:23.909 : [GIPCXCPT][GIPCXCPT] gipcInternalConnectSync: failed sync request, addr 0x19947e90 [0000000000000014] { gipcAddress : name 'ipc://scls_opct_ol9-19-dg1', objFlags 0x0, addrFlags 0x4 }, ret gipcretConnectionRefused (29)
2025-03-25 16:42:23.910 : [GIPCXCPT][GIPCXCPT] gipcInternalConnectSync: failed sync request, addr 0x19948b10 [000000000000001c] { gipcAddress : name 'ipc://scls_opct_ol9-19-dg1', objFlags 0x0, addrFlags 0x4 }, ret gipcretConnectionRefused (29)
2025-03-25 16:42:23.911 : [GIPCXCPT][GIPCXCPT] gipcInternalConnectSync: failed sync request, addr 0x19947e90 [0000000000000024] { gipcAddress : name 'ipc://scls_opct_ol9-19-dg1', objFlags 0x0, addrFlags 0x4 }, ret gipcretConnectionRefused (29)
[ default][ default]u_set_comp_error: comptype '103' : error '29'

So what happens when diagnostic_dest is not writable?

[oracle@ol9-19-dg1/cdb1 ~]# chmod -R 640 /u01/app/oracle/diag
chmod: cannot access '/u01/app/oracle/diag/rdbms': Permission denied
chmod: cannot access '/u01/app/oracle/diag/asm': Permission denied
chmod: cannot access '/u01/app/oracle/diag/crs': Permission denied
chmod: cannot access '/u01/app/oracle/diag/clients': Permission denied
chmod: cannot access '/u01/app/oracle/diag/netcman': Permission denied
chmod: cannot access '/u01/app/oracle/diag/lsnrctl': Permission denied
chmod: cannot access '/u01/app/oracle/diag/tnslsnr': Permission denied
chmod: cannot access '/u01/app/oracle/diag/diagtool': Permission denied
chmod: cannot access '/u01/app/oracle/diag/ofm': Permission denied
chmod: cannot access '/u01/app/oracle/diag/asmtool': Permission denied
chmod: cannot access '/u01/app/oracle/diag/em': Permission denied
chmod: cannot access '/u01/app/oracle/diag/apx': Permission denied
chmod: cannot access '/u01/app/oracle/diag/ios': Permission denied
chmod: cannot access '/u01/app/oracle/diag/afdboot': Permission denied
chmod: cannot access '/u01/app/oracle/diag/gsm': Permission denied
chmod: cannot access '/u01/app/oracle/diag/plsqlapp': Permission denied
chmod: cannot access '/u01/app/oracle/diag/dps': Permission denied
chmod: cannot access '/u01/app/oracle/diag/bdsql': Permission denied
chmod: cannot access '/u01/app/oracle/diag/plsql': Permission denied
chmod: cannot access '/u01/app/oracle/diag/asmcmd': Permission denied
chmod: cannot access '/u01/app/oracle/diag/kfod': Permission denied

[oracle@ol9-19-dg1/cdb1 ~]# alog
tail: cannot open '/u01/app/oracle/diag/rdbms/cdb1/cdb1/trace/alert_cdb1.log' for reading: Permission denied
tail: no files remaining

But now, the logs and traces are all over the place.

So now I have set background_dump_dest to a new directory $ORACLE_HOME/rdmbs/log_test to really see which parameters are being used and what's simply the default:

SQL> show parameter dump_dest

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
background_dump_dest                 string      /u01/app/oracle/product/19.0.0
                                                 /dbhome_1/rdbms/log_test

Alert log #1 $ORACLE_HOME/rdbms/log:

[oracle@ol9-19-dg1/cdb1 /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log]# ls -ltra
-rw-r-----.  1 oracle oinstall     4629 Feb 10 17:43 cdb1_ora_2769.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 12 19:24 cdb1_ora_5386.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 14 15:39 cdb1_ora_3040.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 16 14:18 cdb1_ora_2680.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 18 13:36 cdb1_ora_2396.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 18 17:33 cdb1_ora_2127.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 19 11:16 cdb1_ora_3944.trc
-rw-r-----.  1 oracle oinstall     4629 Feb 26 16:22 cdb1_ora_3604.trc
-rw-r-----.  1 oracle oinstall     4629 Mar  1 18:00 cdb1_ora_2079.trc
-rw-r-----.  1 oracle oinstall     4629 Mar  5 13:26 cdb1_ora_5422.trc
-rw-r-----.  1 oracle oinstall     4629 Mar  9 17:12 cdb1_ora_4959.trc
-rw-r-----.  1 oracle oinstall     4629 Mar 11 20:02 cdb1_ora_2665.trc
-rw-r-----.  1 oracle oinstall     4629 Mar 11 20:58 cdb1_ora_2918.trc
-rw-r-----.  1 oracle oinstall     4629 Mar 11 21:36 cdb1_ora_6979.trc
-rw-r-----.  1 oracle oinstall     4631 Mar 13 21:57 cdb1_ora_22213.trc
-rw-r-----.  1 oracle oinstall     4631 Mar 16 21:16 cdb1_ora_12576.trc
-rw-r-----.  1 oracle oinstall     4629 Mar 22 17:57 cdb1_ora_6279.trc
-rw-r-----.  1 oracle oinstall     4629 Mar 23 15:59 cdb1_ora_3339.trc
-rw-r-----.  1 oracle oinstall     4629 Mar 25 16:42 cdb1_ora_2793.trc
-rw-r-----.  1 oracle oinstall     4629 Apr  3 16:18 cdb1_ora_2912.trc
drwxr-x---.  3 oracle oinstall     8192 Apr  3 16:19 opatch
drwxr-xr-x.  3 oracle oinstall     4096 Apr  3 16:19 .
-rw-r-----.  1 oracle oinstall    52963 Apr  3 16:19 qopatch_log.log
-rw-r-----.  1 oracle oinstall     1826 Apr  3 16:32 alert_cdb1.log

[oracle@ol9-19-dg1/cdb1 /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log]# tail alert_cdb1.log
Thu Apr  3 16:49:51 2025
DIAGNOSTIC_DEST has been reset to a default path: ?#/log
Thu Apr  3 16:50:05 2025
Invalid value given for DIAGNOSTIC_DEST initialization parameter
Thu Apr  3 16:50:05 2025
DIAGNOSTIC_DEST has been reset to a default path: ?#/log
Thu Apr  3 16:50:08 2025
Invalid value given for DIAGNOSTIC_DEST initialization parameter
Thu Apr  3 16:50:08 2025
DIAGNOSTIC_DEST has been reset to a default path: ?#/log

Alert log #2: background_dump_dest:

[oracle@ol9-19-dg1/cdb1 /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log_test]# ls -ltr
total 4
drwxr-xr-x. 17 oracle oinstall 190 Apr  3 16:36 ..
drwxr-xr-x.  2 oracle oinstall  28 Apr  3 16:39 .
-rw-r-----.  1 oracle oinstall 415 Apr  3 16:39 alert_cdb1.log

[oracle@ol9-19-dg1/cdb1 /u01/app/oracle/product/19.0.0/dbhome_1/rdbms/log_test]# tail alert_cdb1.log
Thu Apr  3 16:39:32 2025
WARNING: The background_dump_dest init.ora parameter has been deprecated.
WARNING: Please remove the background_dump_dest parameter from the init.ora file.
WARNING: The diagnostic_dest init.ora parameter now determines the location of the diagnostic data
WARNING: The new location for the background logs and traces is /u01/app/oracle/product/19.0.0/dbhome_1/log/diag/rdbms/cdb1/cdb1/trace

Alert log #3: $ORACLE_HOME/log/diag/rdbms/cdb1/cdb1/trace:

[oracle@ol9-19-dg1/cdb1 /u01/app/oracle/product/19.0.0/dbhome_1/log/diag/rdbms/cdb1/cdb1/trace]# tail alert_cdb1.log
  Tns error struct:
    ns main err code: 12543

TNS-12543: TNS:destination host unreachable
    ns secondary err code: 12560
    nt main err code: 513

TNS-00513: Destination host unreachable
    nt secondary err code: 113
    nt OS err code: 0

This is the actual content of the alert log. This instance is missing its standby, so these entries are correct.

Conclusion

  1. The old dump_dest parameters are deprecated and not used. There seems to be at least one background process that still uses it though. Not sure what it is yet.

  2. **If diagnostic_dest is not writable, the instance will default to $ORACLE_HOME/log/diag/rdbms/cdb1/cdb1/trace

  3. Alert log is in a couple more places, but it's just "empty" with errors letting us know, that it is in fact somewhere else.

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Oracle

Written by

David Budáč
David Budáč