In this Document
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How is the space pressure managed in the Flash Recovery Area - Example. |
APPLIES TO:
Oracle Database - Enterprise Edition - Version 9.0.1.0 to 11.2.0.3 [Release 9.0.1 to 11.2]
Information in this document applies to any platform.
**Checked for relevance on 26-Mar-2012***
PURPOSE
This article explains the handling of space pressure in Flash Recovery Area?
by way of an example.
SCOPE
Oracle DBA's
DETAILS
How is the space pressure managed in the Flash Recovery Area - Example.
Space in the fast recovery area is balanced among backups and archived logs that must be kept?
according to the retention policy,and other files that may be subject to deletion. Oracle Database?
does not delete eligible files from the fast recovery area until the space must be reclaimed for?
some other purpose. Files recently moved to tape are often still available on disk for use in recovery.?
The recovery area can thus serve as a cache for tape. When the fast recovery area is full,?
Oracle Database automatically deletes eligible files to reclaim space in the recovery area as needed.
This note/example below describes actions which can be done if for any reason FRA runs out of space
because automatic deletion of files is not possible,due to retention policy or other reason etc..?
?
?
This testcase has been done with the following configuration:
RMAN> show all;
using target database controlfile instead of recovery catalog
RMAN configuration parameters are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 3;
CONFIGURE BACKUP OPTIMIZATION OFF; # default
CONFIGURE DEFAULT DEVICE TYPE TO DISK;
CONFIGURE CONTROLFILE AUTOBACKUP OFF;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE SBT_TAPE TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DEVICE TYPE SBT_TAPE PARALLELISM 1 BACKUP TYPE TO BACKUPSET; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE SBT_TAPE TO 1; # default
CONFIGURE CHANNEL DEVICE TYPE 'SBT_TAPE' PARMS 'SBT_LIBRARY=oracle.disksbt,ENV=(BACKUP_DIR=/tmp/)';
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/opt/oracle/product/1010/dbs/snapcf_db10g.f'; # default
When the space used in the Flash Recovery Area goes above 85% the we will get?
the following warning in the alert log:
Wed Jun 15 21:51:19 2005
Errors in file /opt/oracle/product/1010/admin/db10g/udump/db10g_ora_13900.trc:
ORA-19815: WARNING: db_recovery_file_dest_size of 1073741824 bytes is 86.07% used,and has 149591552 remaining bytes available.
************************************************************************
You have following choices to free up space from flash recovery area:
1. Consider changing RMAN RETENTION POLICY. If you are using Data Guard,then consider changing RMAN ARCHIVELOG DELETION POLICY.
2. Back up files to tertiary device such as tape using RMAN
BACKUP RECOVERY AREA command.
3. Add disk space and increase db_recovery_file_dest_size parameter to
reflect the new space.
4. Delete unnecessary files using RMAN DELETE command. If an operating
system command was used to delete files,then use RMAN CROSSCHECK and
DELETE EXPIRED commands.
************************************************************************
When the Flash Recovery Area is completely full then we get a error message as follow:
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on ORA_DISK_1 channel at 06/15/2005 22:39:22
ORA-19809: limit exceeded for recovery files
ORA-19804: cannot reclaim 52428800 bytes disk space from 1073741824 limit
To make space reclaimable we have the following options:
1)?The space occupied by archivelogs created in the Flash Recovery Area?
???? would become reclaimable in 2 circumstances:
A) If the free space becomes less then 15% in the Flash Recovery Area then all?
???? the archivelogs in the Flash Recovery Area which are not needed for recovery?
???? by the current backups in the FRA will become obsolete and the space occupied?
???? will be shown in the SPACE RECLAIMABLE column of V$RECOVERY_FILE_DEST.
Output BEFORE free space less than 15%:
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
-------------------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 913181184 0 11
Output AFTER free space less then 15%:(SPACE_RECLAIMABLE column it is now not zero)
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
--------------------------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 913181184 2124288 11
RMAN> report obsolete;
RMAN retention policy will be applied to the command
RMAN retention policy is set to redundancy 3
Report of obsolete backups and copies
Type Key Completion Time Filename/Handle
-------------------- ------ ------------------ --------------------
Archive Log 51 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_110_1c0mj1b2_.arc
Archive Log 52 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_111_1c0mj8co_.arc
Archive Log 53 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_112_1c0mj9tp_.arc
Archive Log 54 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_113_1c0mjh6j_.arc
Archive Log 55 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_114_1c0mjn90_.arc
B) If the archivelogs have been backed up (either to the Flash Recovery Area itself?
??? or to another destination) and the archivelog not deleted. Then the space occupied?
??? by that archivelog will be marked as reclaimable.
RMAN> backup archivelog all;
Starting backup at 15-JUN-05
current log archived
using channel ORA_DISK_1
channel ORA_DISK_1: starting archive log backupset
channel ORA_DISK_1: specifying archive log(s) in backup set
input archive log thread=1 sequence=110 recid=51 stamp=561071961
input archive log thread=1 sequence=111 recid=52 stamp=561071968
input archive log thread=1 sequence=112 recid=53 stamp=561071969
input archive log thread=1 sequence=113 recid=54 stamp=561071975
input archive log thread=1 sequence=114 recid=55 stamp=561071980
input archive log thread=1 sequence=115 recid=56 stamp=561074872
channel ORA_DISK_1: starting piece 1 at 15-JUN-05
channel ORA_DISK_1: finished piece 1 at 15-JUN-05
piece handle=/opt/oracle/product/1010/dbs/ora_flash_area/DB10G/backupset/2005_06
_15/o1_mf_annnn_TAG20050615T220755_1c0pc73n_.bkp comment=NONE
channel ORA_DISK_1: backup set complete,elapsed time: 00:00:09
Finished backup at 15-JUN-05
RMAN> report obsolete;
RMAN retention policy will be applied to the command
RMAN retention policy is set to redundancy 3
Report of obsolete backups and copies
Type Key Completion Time Filename/Handle
-------------------- ------ ------------------ --------------------
Archive Log 51 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_110_1c0mj1b2_.arc
Archive Log 52 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_111_1c0mj8co_.arc
Archive Log 53 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_112_1c0mj9tp_.arc
Archive Log 54 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_113_1c0mjh6j_.arc
Archive Log 55 15-JUN-05 /opt/oracle/product/1010/dbs/ora_
flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_114_1c0mjn90_.arc
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
---------------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 934593024 11767296 13
Here we see that 6 archivelogs have been backed up. Out of the 6 archivelogs?
5 are not needed for recovery and are hence obsolete. But 1 of the archivelogs
is needed for recovery and hence is not shown in the report obsolete. But still?
the space occupied by that archivelog will be added to the reclaimable space.
2)?When the Flash Recovery Area is full and there is no space available to?
??? create archivelogs in the Flash Recovery Area. We will get the following error
??? in the alert log:
Wed Jun 15 23:01:09 2005
Errors in file /opt/oracle/product/1010/admin/db10g/udump/db10g_ora_13754.trc:
ORA-19809: limit exceeded for recovery files
ORA-19804: cannot reclaim 1032704 bytes disk space from 1073741824 limit
ARCH: Error 19809 Creating archive log file to '/opt/oracle/product/1010/dbs/ora_flash_area/DB10G/archivelog/2005_06_15/o1_mf_1_116_0_.arc'
ARCH: All standby destinations failed; successful archival assumed
ARCH: Failed to archive thread 1 sequence 116 (19809)
Wed Jun 15 23:01:27 2005
ARC1: Evaluating archive thread 1 sequence 116
ARC1: Archiving not possible: No primary destinations
ARC1: Failed to archive thread 1 sequence 116 (4)
ARCH: Archival stopped,error occurred. Will continue retrying
Wed Jun 15 23:01:27 2005
ORACLE Instance db10g - Archival Error
ARCH: Connecting to console port...
Wed Jun 15 23:01:27 2005
ORA-16014: log 2 sequence# 116 not archived,no available destinations
ORA-00312: online log 2 thread 1: '/opt/oracle/product/1010/oradata/db10g/redo02.log'
ARCH: Connecting to console port...
ARCH:
Wed Jun 15 23:01:27 2005
ORA-16014: log 2 sequence# 116 not archived,no available destinations
ORA-00312: online log 2 thread 1: '/opt/oracle/product/1010/oradata/db10g/redo02.log'
3)?To free space in the FRA we could do take a backup of the Flash Recovery Area?
??? using the command BACKUP RECOVERY AREA.
??? This command will take the backup of al the files in the FRA to tape only.?
??? After this the space occupied by the files in the FRA will be marked as reclaimable.
Make sure that you have configured channels for backups to tape for this command to succeed.
RMAN> backup recovery area;
Starting backup at 15-JUN-05
released channel: ORA_DISK_1
using channel ORA_SBT_TAPE_1
specification does not match any datafilecopy in the repository
channel ORA_SBT_TAPE_1: starting archive log backupset
channel ORA_SBT_TAPE_1: specifying archive log(s) in backup set
input archive log thread=1 sequence=116 recid=57 stamp=561079349
channel ORA_SBT_TAPE_1: starting piece 1 at 15-JUN-05
channel ORA_SBT_TAPE_1: finished piece 1 at 15-JUN-05
piece handle=28gn2p4a_1_1 comment=API Version 2.0,MMS Version 8.1.3.0
channel ORA_SBT_TAPE_1: backup set complete,elapsed time: 00:00:02
input backupset count=58 stamp=561073729 creation_time=15-JUN-05
channel ORA_SBT_TAPE_1: starting piece 1 at 15-JUN-05
piece handle=1qgn2ji1_1_2 comment=API Version 2.0,MMS Version 8.1.3.0
channel ORA_SBT_TAPE_1: finished piece 1 at 15-JUN-05
channel ORA_SBT_TAPE_1: backup set complete,elapsed time: 00:00:25
input backupset count=60 stamp=561073791 creation_time=15-JUN-05
channel ORA_SBT_TAPE_1: starting piece 1 at 15-JUN-05
piece handle=1sgn2jjv_1_2 comment=API Version 2.0,MMS Version 8.1.3.0
....
input backupset count=66 stamp=561076762 creation_time=15-JUN-05
channel ORA_SBT_TAPE_1: starting piece 1 at 15-JUN-05
piece handle=22gn2mgq_1_2 comment=API Version 2.0,elapsed time: 00:00:01
Finished backup at 15-JUN-05
Now the output of the query would look like this:
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
--------------------------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 623138304 623138304 7
Note that this command will not delete the files from the FRA. The files would be?
deleted whenever any space is required for any new operation.
4)?If suppose the FRA is full and the reclaimable space is 0 or insufficient?
???? and we cannot backup the Flash Recovery Area to tape. Then to free?
???? space we may delete unwanted files which are not yet obsolete by the following method:
A)?Use the RMAN DELETE command to delete some files from the FRA:
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
------------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 633155072 0 8
RMAN> delete backupset 45;
using channel ORA_DISK_1
using channel ORA_SBT_TAPE_1
List of Backup Pieces
BP Key BS Key Pc# Cp# Status Device Type Piece Name
------- ------- --- --- ----------- ----------- ----------
52 45 1 1 AVAILABLE DISK opt/oracle/product/1010/dbs/ora
_flash_area/DB10G/backupset/2005_06_15/o1_mf_ncsnf_TAG20050615T215053_1c0odcbg_.bkp
Do you really want to delete the above objects (enter YES or NO)? yes
deleted backup piece
backup piece handle=/opt/oracle/product/1010/dbs/ora_flash_area/DB10G/backupset/
2005_06_15/o1_mf_ncsnf_TAG20050615T215053_1c0odcbg_.bkp recid=52 stamp=561073891
Deleted 1 objects
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
-------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 630189568 0 7
B)?You can delete the files from the OS using the OS command and then run?
???? the RMAN CROSSCHECK command and DELETE EXPIRED command to free the space.
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
-------------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 630189568 0 7
[oracle@incq073ac 2005_06_15]$ ls -l
total 1016
-rw-r----- 1 oracle dba 1033216 Jun 15 23:22 o1_mf_1_116_1c0tpxb6_.arc
[oracle@incq073ac 2005_06_15]$ rm *
[oracle@incq073ac 2005_06_15]$
RMAN> crosscheck archivelog all;
released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=142 devtype=DISK
validation failed for archived log
archive log filename=/opt/oracle/product/1010/dbs/ora_flash_area/DB10G/archivelo
g/2005_06_15/o1_mf_1_116_1c0tpxb6_.arc recid=57 stamp=561079349
validation succeeded for archived log
archive log filename=/opt/oracle/product/1010/dbs/ora_flash_area/DB10G/archivelo
g/2005_06_16/o1_mf_1_117_1c1ds0cf_.arc recid=58 stamp=561097849
Crosschecked 2 objects
RMAN> delete expired archivelog all;
released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=142 devtype=DISK
List of Archived Log Copies
Key Thrd Seq S Low Time Name
------- ---- ------- - --------- ----
57 1 116 X 15-JUN-05 /opt/oracle/product/1010/dbs/ora_flash_area/DB1
0G/archivelog/2005_06_15/o1_mf_1_116_1c0tpxb6_.arc
Do you really want to delete the above objects (enter YES or NO)? yes
deleted archive log
archive log filename=/opt/oracle/product/1010/dbs/ora_flash_area/DB10G/archivelo
g/2005_06_15/o1_mf_1_116_1c0tpxb6_.arc recid=57 stamp=561079349
Deleted 1 EXPIRED objects
SQL> SELECT * FROM V$RECOVERY_FILE_DEST;
NAME
----------------------------------------------------------
SPACE_LIMIT SPACE_USED SPACE_RECLAIMABLE NUMBER_OF_FILES
----------- ---------- ----------------- ---------------
/opt/oracle/product/1010/dbs/ora_flash_area
1073741824 629156864 0 6
Refer?Note 829755.1?: Space issue in Flash Recovery Area( FRA )?
