WARNING: This web is not used anymore. Please use PDBService.BackupPolicyManagers instead!
 

Backup Implementation

Summary

The implementation of a backup strategy based on Oracle RMAN 10g is described in this document. This strategy allows for (1) backups to tape and (2) backups to disk (also called flash backups). Flash backups help to substantially reduce the recovery time for many common recovery scenarios. This new RMAN scripting implementation is built as an extension of an existing (old) infrastructure that had prove very good stability. Existing functionalities are kept and new ones are introduced. The backups are scheduled and 'pushed' from a central server and alarms are generated by the tape system if backups are not performed.

Types of backup

  • backup to tape - it uses IBM Tivoli Storage Manager (TSM) product managed by IT-FIO group. Oracle RMAN has dedicated drivers to connect to TSM and manage backups stored in tapes in a special backup format. There are different kind of backups done to tape:
    • Full backup (level 0) - a complete copy of the database and control files
    • Differential backup (level 1) - copy of blocks changed since latest level 0 or level 1 backup
    • Cumulative backup (level 1) - copy of blocks changed since latest level 0 backup
    • Archive logs - copy of the archive logs (files containing the log of the operations done in the database)

  • Backup to disk - Oracle RMAN copies all datafiles into the flash recovery area (typically on a different storage array than the datafiles). We use a technique called "Incrementally Updated Backups" to maintain this type of backup. The disk backup copy of the DB is kept 2 days behind production and allows for DB recoveries in that time frame.

Notes:

  • Backup retention is set to 31 days. This guarantees that a copy of the database can be recovered in a time window of 31 days (typically a larger winwod will be available but is not guaranteed)
  • Oracle's block change tracking feature is used to significantly reduce the latency and weight of the incremental DB backups (only changed DB blocks are read during a backup with this optimization)
  • A dedicated system for test recoveries is available. Typical use of this system are: periodic test recoveries, point in time recoveries, tape-backup based disaster recovery.

Generic schedule (for production service)

  • Backup to Tape (RACs)
    • Full - 0T - Every 2 weeks
    • Differential - 1D - 4x/week
    • Cumulative - 1C - 2x/week
    • Archive logs - A - every 1 hour (depends on DB)

  • Backup to Disk
    • Recovery copy - daily
    • Retention - 31 days windows for RACs

  • Delete obsolete
    • Daily (include manual deletion of backup set on disk)

Edit | Attach | Watch | Print version | History: r5 < r4 < r3 < r2 < r1 | Backlinks | Raw View | WYSIWYG | More topic actions
Topic revision: r5 - 2007-01-25 - LucaCanali
 
    • Cern Search Icon Cern Search
    • TWiki Search Icon TWiki Search
    • Google Search Icon Google Search

    PSSGroup All webs login

This site is powered by the TWiki collaboration platform Powered by PerlCopyright & 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
or Ideas, requests, problems regarding TWiki? use Discourse or Send feedback