Use
This
procedure tells you how to check the archiving parameters and ARCHIVELOG mode
for your Oracle database and, if necessary, how to change these.
It
is very important that:
·
The
database runs in ARCHIVELOG mode
·
Automatic archiving is enabled
After
correct installation of an SAP system, the Oracle database meets both these
criteria. In this case, the online redo log files are automatically archived
when full (that is, following a redo log switch). This is important because it
allows the online redo log files to be reused for fresh archive data, so that
archiving of the log files can continue at all times.
Prerequisites
The
following parameters in the init.ora file
control the archiving process for the Oracle database:
Parameter
|
Note
|
log_archive_start
= true
|
Preset by SAP
|
log_archive_dest =
<directory>/<file prefix>
|
Part of the file name
|
log_archive_format =
<Oracle default>
|
Use the Oracle default
|
log_archive_start =
true causes
the background archive process ARCH to be started automatically when the
database is started. This means that automatic archiving is
enabled.
log_archive_dest defines the archive directory
of the online redo log files for archiving. It is delivered with the
specification of the following SAP standard path (this example is for a single
instance installation on UNIX):
OS>
<SAPDATA_HOME>/saparch/<ORACLE_SID>arch
See
SAP Note 316642 for information on how to avoid an "archiver stuck" error by
changing the archive directory.
For
more information, see Environment Variables
(UNIX) and Environment Variables
(Windows).
The Oracle database names the offline redo log files
using the string <ORACLE_SID>arch followed by the log sequence
number.
You can back up the offline
redo log files with BR*Tools. The offline redo log files are the copies of
the online redo log files saved in the archive directory.
Procedure
...
1.
Make
sure that:
¡
The
archive directory (under UNIX: oraarch)
exists.
¡
The
directory is not write-protected.
¡
The
directory has enough free space. Otherwise, the archiving process cannot
archive any log files and no further actions are possible on the database
(this is known as “Archiver Stuck”).
For more information on the BR*Tools commands
mentioned below, see Altering the Database
Instance with BR*Tools and -f
dbalter.
2.
Check
the archiving status of the database by choosing Instance
Management ® Show
instance status in BR*Tools.
The system displays database instance details.
3.
Check
that:
¡
Archivelog
mode is set
to ARCHIVELOG
¡
Archiver
status is set
to STARTED
4.
If you
need to reset ARCHIVELOG mode, do this in one of the following
ways:
a.
Do one
of the following:
§
Choose
Instance Management ® Alter database
instance in BRGUI or BRTOOLS and choose the action Set archivelog mode.
§
Enter
the command brspace –f dbalter
–a archlog from the command line.
§
Enter
the following commands in the Oracle tool SQLPLUS:
SQLPLUS> connect / as sysdba
SQLPLUS> startup mount
SQLPLUS> alter database archivelog;
SQLPLUS> alter database open;
SQLPLUS> archive log list
SQLPLUS> startup mount
SQLPLUS> alter database archivelog;
SQLPLUS> alter database open;
SQLPLUS> archive log list
BRSPACE or SQLPLUS reconfigures the database to set
ARCHIVELOG mode on.
b.
Repeat
steps 2 and 3 to check that ARCHIVELOG has been set correctly.
5.
If you
need to enable automatic archiving (that is, to start the ARCH process), do
the following:
a.
Enter
the following commands in the Oracle tool SQLPLUS:
SQLPLUS> connect / as sysdba
SQLPLUS> alter system archive log
start;
SQLPLUS> archive log list
b.
Repeat
steps 2 and 3 to check that ARCHIVELOG has been set correctly.
0 comments:
Post a Comment