Databases Reference
In-Depth Information
5.
Optionally check for the member's existence in the onlinelog directory at the fast recovery
area destination:
$ asmcmd
ASMCMD> cd +FRA/cdb1/onlinelog
ASMCMD> ls -ls
Type Redund Striped Time Sys Block_Size Blocks Bytes Space Name
ONLINELOG UNPROT COARSE AUG 02 21:00:00 Y 512 204801 104858112 106954752
group_4.268.790292145
This has a small problem, however. As you can see, there is only one log file member for that group. Best
practices suggest that there should be at least two members per group to eliminate any single point of failure. You can
accomplish this by specifying two additional parameters for the online redo log creation, shown in the following steps:
Set the parameters
db_create_online_log_dest_1
and
db_create_online_log_dest_2
to
the fast recovery area location:
1.
SQL> alter system set db_create_online_log_dest_1 = '+FRA';
System altered.
SQL> alter system set db_create_online_log_dest_2 = '+FRA';
System altered.
2.
Now add the log file group without mentioning any specific file or directory names:
SQL> alter database add logfile group 5;
Database altered.
3.
Confirm the creation of online redo log files by selecting the member names from the data
dictionary view V$LOGFILE:
SQL> select member
2 from v$logfile
3 where group# = 5;
MEMBER
--------------------------------------------------------------------------------
+FRA/cdb1/onlinelog/group_5.268.790292145
+FRA/cdb1/onlinelog/group_5.265.790292147
This confirms that two members were created for the log file group, not one.
4.
Optionally, you can also verify that these files were created in the fast recovery area
destination:
$ cd +FRA/cdb1/onlinelog
$ ls -l
total 205016
-rw-r----- 1 oracle oinstall 104858112 Oct 10 23:43 o1_mf_4_2lrt26ox_.log
-rw-r----- 1 oracle oinstall 104858112 Oct 10 23:43 o1_mf_4_2lrt285q_.log
