2

I found this definition on WEB:

A logical grouping of backup files -- the backup pieces -- that are created when you issue an RMAN backup command. A backup set is RMAN’s name for a collection of files associated with a backup. A backup set is composed of one or more backup pieces.

but I don't understand why when I make one backup of whole database the rman creates several backupsets

Here is the output about one backup that I make (I've used parallelism 4)

[oracle@orcl12 ~]$ rman target /

Recovery Manager: Release 12.2.0.1.0 - Production on Sat Jul 20 12:48:52 2019

Copyright (c) 1982, 2017, Oracle and/or its affiliates.  All rights reserved.

connected to target database: ORCL (DBID=1525136414)

RMAN> list backup;

using target database control file instead of recovery catalog

List of Backup Sets
===================


BS Key  Size       Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ -------------------
161     3.92M      DISK        00:00:01     20/07/2019 12:06:12
        BP Key: 161   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120610
        Piece Name: /u01/app/oracle/recovery_area/ORCL/backupset/2019_07_20/o1_mf_annnn_TAG20190720T120610_gm6ch3t2_.bkp

  List of Archived Logs in backup set 161
  Thrd Seq     Low SCN    Low Time            Next SCN   Next Time
  ---- ------- ---------- ------------------- ---------- ---------
  1    58      14688057   20/07/2019 11:55:34 14693433   20/07/2019 12:06:09

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
162     Full    307.59M    DISK        00:03:59     20/07/2019 12:10:15
        BP Key: 162   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F4405983DB33E47E055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6chcwh_.bkp
  List of Datafiles in backup set 162
  Container ID: 3, PDB Name: ORCLPDB
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  10      Full 14693446   20/07/2019 12:06:16              NO    /u01/app/oracle/oradata/orcl/orclpdb/sysaux01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
163     Full    276.60M    DISK        00:04:11     20/07/2019 12:10:27
        BP Key: 163   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F43A22D9E7528CCE055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6chg3m_.bkp
  List of Datafiles in backup set 163
  Container ID: 2, PDB Name: PDB$SEED
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  6       Full 1441967    12/01/2019 11:41:59              NO    /u01/app/oracle/oradata/orcl/pdbseed/sysaux01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
164     Full    503.65M    DISK        00:05:59     20/07/2019 12:12:14
        BP Key: 164   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6ch8s4_.bkp
  List of Datafiles in backup set 164
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  3       Full 14693445   20/07/2019 12:06:16              NO    /u01/app/oracle/oradata/orcl/sysaux01.dbf
  7       Full 14693445   20/07/2019 12:06:16              NO    /u01/app/oracle/oradata/orcl/users01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
165     Full    738.59M    DISK        00:06:22     20/07/2019 12:12:37
        BP Key: 165   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6ch803_.bkp
  List of Datafiles in backup set 165
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  1       Full 14693444   20/07/2019 12:06:15              NO    /u01/app/oracle/oradata/orcl/system01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
166     Full    285.26M    DISK        00:01:08     20/07/2019 12:13:58
        BP Key: 166   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6cvr4x_.bkp
  List of Datafiles in backup set 166
  Container ID: 4, PDB Name: HOMOL
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  57      Full 14693594   20/07/2019 12:12:54              NO    /u01/app/oracle/oradata/orcl/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/datafile/o1_mf_sysaux_glh6b049_.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
167     Full    198.24M    DISK        00:01:35     20/07/2019 12:15:22
        BP Key: 167   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F43A22D9E7528CCE055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6cxvsl_.bkp
  List of Datafiles in backup set 167
  Container ID: 2, PDB Name: PDB$SEED
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  5       Full 1441967    12/01/2019 11:41:59              NO    /u01/app/oracle/oradata/orcl/pdbseed/system01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
168     Full    222.91M    DISK        00:02:53     20/07/2019 12:15:49
        BP Key: 168   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F4405983DB33E47E055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6cxov8_.bkp
  List of Datafiles in backup set 168
  Container ID: 3, PDB Name: ORCLPDB
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  9       Full 14693605   20/07/2019 12:13:22              NO    /u01/app/oracle/oradata/orcl/orclpdb/system01.dbf
  12      Full 14693605   20/07/2019 12:13:22              NO    /u01/app/oracle/oradata/orcl/orclpdb/users01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
169     Full    204.08M    DISK        00:02:21     20/07/2019 12:17:20
        BP Key: 169   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d1dhk_.bkp
  List of Datafiles in backup set 169
  Container ID: 4, PDB Name: HOMOL
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  56      Full 14693679   20/07/2019 12:15:52              NO    /u01/app/oracle/oradata/orcl/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/datafile/o1_mf_system_glh69zz4_.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
170     Full    3.07M      DISK        00:02:04     20/07/2019 12:18:00
        BP Key: 170   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F4405983DB33E47E055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d4lp2_.bkp
  List of Datafiles in backup set 170
  Container ID: 3, PDB Name: ORCLPDB
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  11      Full 14693696   20/07/2019 12:16:40              NO    /u01/app/oracle/oradata/orcl/orclpdb/undotbs01.dbf
  60      Full 14693696   20/07/2019 12:16:40              NO    /u01/app/oracle/product/12.2.0/dbhome_1/dbs/brelele

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
171     Full    7.98M      DISK        00:00:36     20/07/2019 12:18:13
        BP Key: 171   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F4405983DB33E47E055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d5kdw_.bkp
  List of Datafiles in backup set 171
  Container ID: 3, PDB Name: ORCLPDB
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  55      Full 14693724   20/07/2019 12:17:54              NO    /u01/app/oracle/oradata/orcl/ORCL/7F4405983DB33E47E055FAC8EF8905E8/datafile/o1_mf_rman_gldpgddc_.dbf
  61      Full 14693724   20/07/2019 12:17:54              NO    /u01/app/oracle/product/12.2.0/dbhome_1/dbs/brelele2

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
172     Full    37.42M     DISK        00:00:34     20/07/2019 12:18:44
        BP Key: 172   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/7F43A22D9E7528CCE055FAC8EF8905E8/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d61cl_.bkp
  List of Datafiles in backup set 172
  Container ID: 2, PDB Name: PDB$SEED
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  8       Full 1441967    12/01/2019 11:41:59              NO    /u01/app/oracle/oradata/orcl/pdbseed/undotbs01.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
173     Full    2.57M      DISK        00:00:31     20/07/2019 12:19:01
        BP Key: 173   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d6nnb_.bkp
  List of Datafiles in backup set 173
  Container ID: 4, PDB Name: HOMOL
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  58      Full 14693749   20/07/2019 12:18:34              NO    /u01/app/oracle/oradata/orcl/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/datafile/o1_mf_undotbs1_glh6b04c_.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
174     Full    1.04M      DISK        00:00:32     20/07/2019 12:19:16
        BP Key: 174   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d7mhm_.bkp
  List of Datafiles in backup set 174
  Container ID: 4, PDB Name: HOMOL
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  59      Full 14693756   20/07/2019 12:18:51              NO    /u01/app/oracle/oradata/orcl/ORCL/8D6E79BBBC2A140CE0531400A8C06C3B/datafile/o1_mf_users_glh795h1_.dbf

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
175     Full    16.57M     DISK        00:00:16     20/07/2019 12:19:21
        BP Key: 175   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T120613
        Piece Name: /u01/app/oracle/recovery_area/ORCL/backupset/2019_07_20/o1_mf_nnndf_TAG20190720T120613_gm6d7q9r_.bkp
  List of Datafiles in backup set 175
  File LV Type Ckp SCN    Ckp Time            Abs Fuz SCN Sparse Name
  ---- -- ---- ---------- ------------------- ----------- ------ ----
  4       Full 14694166   20/07/2019 12:19:15 14694171     NO    /u01/app/oracle/oradata/orcl/undotbs01.dbf
  28      Full 14694166   20/07/2019 12:19:15              NO    /u01/app/oracle/oradata/orcl/ORCL/datafile/o1_mf_haha_gb1k1h6b_.dbf

BS Key  Size       Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ -------------------
176     4.99M      DISK        00:00:00     20/07/2019 12:19:37
        BP Key: 176   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T121936
        Piece Name: /u01/app/oracle/recovery_area/ORCL/backupset/2019_07_20/o1_mf_annnn_TAG20190720T121936_gm6d89jz_.bkp

  List of Archived Logs in backup set 176
  Thrd Seq     Low SCN    Low Time            Next SCN   Next Time
  ---- ------- ---------- ------------------- ---------- ---------
  1    59      14693433   20/07/2019 12:06:09 14694370   20/07/2019 12:19:30

BS Key  Type LV Size       Device Type Elapsed Time Completion Time
------- ---- -- ---------- ----------- ------------ -------------------
177     Full    18.09M     DISK        00:00:05     20/07/2019 12:19:54
        BP Key: 177   Status: AVAILABLE  Compressed: NO  Tag: TAG20190720T121948
        Piece Name: /u01/app/oracle/recovery_area/ORCL/autobackup/2019_07_20/o1_mf_s_1014121189_gm6d8tj6_.bkp
  SPFILE Included: Modification time: 20/07/2019 12:18:10
  SPFILE db_unique_name: ORCL
  Control File Included: Ckp SCN: 14694951     Ckp time: 20/07/2019 12:19:49

shouldn't the rman creates one backupset for one backup and in this backupset include all backup pieces?

My RMAN configurations:

RMAN configuration parameters for database with db_unique_name ORCL are:
CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default
CONFIGURE BACKUP OPTIMIZATION ON;
CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default
CONFIGURE CONTROLFILE AUTOBACKUP ON;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default
CONFIGURE DEVICE TYPE DISK PARALLELISM 4 BACKUP TYPE TO BACKUPSET;
CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default
CONFIGURE MAXSETSIZE TO UNLIMITED; # default
CONFIGURE ENCRYPTION FOR DATABASE OFF; # default
CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default
CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default
CONFIGURE RMAN OUTPUT TO KEEP FOR 7 DAYS; # default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default
CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/u01/app/oracle/product/12.2.0/dbhome_1/dbs/snapcf_orcl.f'; # default
  • Please, show the command you've executed to get backup, i.e. backup database ... Also, execute SHOW ALL in rman and show the output. – Eduard Okhvat Jul 22 at 2:57
  • I get to add my configurations. I make the backup using backup database plus archivelog delete input; – Danilo Neto Jul 22 at 16:41
1

Using backup database plus archivelog rman will make several steps:

  1. log switch (creates new archivelog)
  2. backup of archivelogs
  3. backup of datafiles
  4. log switch (creates new archivelog)
  5. backup of archivelogs for the time of db backup
  6. backup of controlfile and spfile;

So here rman will create at least 4 backupsets: two - with archivelogs, one - with datafiles, and one with CF and spfile.

If you are using parallelism of 4 - then rman will work in 4 processes(threads), and every process will generate its own backupset.

For datafiles rman will divide this work between 4 processes, and every process will backup their datafiles.

The same for the archivelogs - if there are many - you'll see 4 backupsets for them.

  • Perfect! I've altered the parallelism for 1 (default) and made the backup again. In the end the RMAN has created 4 backupsets like you said. – Danilo Neto Jul 23 at 19:36
2

Also from the Database Backup and Recovery User's Guide.

The total number and size of backup sets depends mostly on an internal RMAN algorithm. However, you can influence RMAN behavior with the MAXSETSIZE parameter in the CONFIGURE or BACKUP command. By limiting the size of the backup set, the parameter indirectly limits the number of files in the set and can possibly force RMAN to create additional backup sets. Also, you can specify BACKUP ... FILESPERSET to specify the maximum number of files in each backup set.

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