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Recovery and Backup RMAN. TIER 1 Experience, status and questions. Carlos Fernando Gamboa, BNL Gordon L Brown, RAL. Meeting at CNAF June 12-13 of 2007, Bologna, Italy. Table of Content. Factors that define a backup policy Backup strategy (from previous DBA SARA workshop)
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Recovery and BackupRMAN TIER 1 Experience, status and questions. Carlos Fernando Gamboa, BNL Gordon L Brown, RAL Meeting at CNAF June 12-13 of 2007, Bologna, Italy
Table of Content • Factors that define a backup policy • Backup strategy (from previous DBA SARA workshop) • Site status RMAN configuration • RMAN implementation problems • Experience • Questions • Example (Presented by Gordon L Brown) 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Factors that define a backup policy • Maximum % of data that can be lost - Retention Policy: How long are the backups retained and how far is acceptable to recover the database? - How many copies per file must be retained? • Time required to recover the service - Faster recovery through disk media but more expensive than tape. - Minimum % downtime of the service during recovery • Cost/Benefit of backup policy and recovery strategy Site resources 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
CERN backup strategy RMAN - backups to tape • Level 0, every 2 weeks • level 1 cumulative, twice per week • level 1 differential, every day (except when the cumulative backup is done) • archivelogs backups, every 30 minutes • Retention: recovery window of 31 days (may change) RMAN - backups to disk: • Daily refreshed with incremental recovery • Image copy delayed from production (2 days) • Allows for very fast recovery for many failure scenarios • Regular tests of recovery procedure • Open point: disaster recovery / dataguard From:Gordon D. Brown e-Science, RAL3D Workshop, SARA, Netherlands 20/21 March 2007 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Summary Sites RMAN implementation 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Summary sites RMAN implementation 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
RMANImplementation Problems • Control file block problem An archivelog file was not found on the control file. • Different archivelog format on each node of the RAC. • Service interruption to change archivelog destination. 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Sites experience with RMAN • RMAN deployment on FTS. • RMAN basic configuration through OEM. • Most of the sites are validating RMAN scripts for the 3D database backup and learning how to use this tool. • TRIUNF experience with compression • It seems too heavy on the oracle RAC node, and does not seem to compress really efficiently. • Running bzip2 on a 1.9 GB compressed RMAN file results in a file that is further compressed to 1.6 GB. 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Sites Experience with RMAN (cont.) • Backup process “Testing is tedious; with our currently-configured backup server a full backup takes almost 2 hours”. • CNAF has experienced restore with single instance with local file system (ext3) and with ASM for the recovery area in remote storage system. 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Questions • Integrate RMAN / TIVOLI Cost / benefit ratio? • OEM - Cron jobs to implement backups or configure them by using OEM? - How to configure OEM to send alerts when service is down? • RMAN implemented as cron jobs - Can cron jobs use ASM disk as backup destination when using RMAN scripts? - Is it necessary to implement RMAN scripts on each node to archivelog and delete them? 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Questions (cont.) • How important is to implement an independent RMAN catalog Db? • Is there any reason to limit the size of an RMAN-generated file for disk-based backup? • Are there any backup options that we should use that help to optimize RMAN restores? • What is the recommended number of backups that sites retain? • Has someone experience to run grid control as a VMWare Virtual Machine? • Examples for use dmbs_scheduler to manage RMAN jobs node-independent on different Oracle RAC? 3D LCG Database Administration workshop at CNAF - June 12-13, 2007
Thanks to the people that contributed to this presentation. Luis Diaz Denice Deatrich Dave Wei Federico Bonifazi Olli Tourunen Doris Wochele Gordon L. Brown 3D LCG Database Administration workshop at CNAF - June 12-13, 2007