Note_Tech

All technological notes.

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Backup - Duplexing Backup Sets

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• Backup - Duplexing Backup Sets
  • Duplexing Backup Sets
  • Command
  • Lab: Backing up backup set

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Duplexing Backup Sets

• A copy of a duplexed backup set:

  • a copy of each backup piece in the backup set, with each copy getting a unique copy number (for example, 0tcm8u2s_1_1 and 0tcm8u2s_1_2).

• Maximum:

  • four copies of a backup set simultaneously

• Duplexing applies only to backup sets, not image copies.

  • cannot specify the BACKUP... COPIES when creating image copy backups
  • CONFIGURE... BACKUP COPIES setting is ignored for image copy backups.

• Device Type:

  • It is not possible to duplex backup sets to the fast recovery area. 不能 FRA
  • can duplex backups to either disk or tape,
  • cannot duplex backups to tape and disk simultaneously.
  • DISK channels
    • use FORMAT option to specify multiple copies to different physical disks.
  • SBT channels
    • if you use a media manager that supports Version 2 of the SBT API, then the media manager automatically writes each copy to a separate medium (for example, a separate tape).
    • When backing up to tape, ensure that the number of copies does not exceed the number of available tape devices.

• Performance:

  • Duplexed backups require additional resources.
  • e,g,. if a nonduplexed backup to tape uses three RMAN channels (each requiring one tape drive), then duplexing this backup (making two copies) requires six tape drives.

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Command

CONFIGURE...BACKUP COPIES
BACKUP...COPIES

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Lab: Backing up backup set

-- backup to a path in 2 copies
BACKUP AS BACKUPSET FORMAT '/home/oracle/backup/%U'
COPIES 2
INCREMENTAL LEVEL 0
DATABASE;

• Confirm

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