1. Backups CSCI N321 – System and Network Administration Copyright © 2000, 2011 by Scott Orr and the Trustees of Indiana University

2. Section Overview Storage Hierarchy Backup Characteristics Backup Media Backups Tools and Plans

3. References COIT 13146 Study Guide Chapter 12

4. Storage Hierarchy Solid State Drive (SSD) RAM Cache Magnetic Drive Optical Disks Tape Speed/Cost Storage Capacity Volatile Non-Volatile

5. Why Backups? Accidental deletions or modification Hardware failures Upgrades and Migrations Security incidents Disaster Recovery Lawsuits?

6. Backup Plan Characteristics Ease of use Automation of backups Selective file/directory restores Time scheduling Backup verification Offsite copies Portability Media Lifecycle!!! Deduplication

7. Backup Media USB Hard Drives/Sticks CD-R/RW and DVD±R/RW Drives Disks Tape 4mm DAT 8mm DLT LT0 (1,2,3,…) Rewinding vs. Non-Rewinding Libraries/Stackers/Jukeboxes

8. Linux Backup tools dump and restore filesystem backups Support for incremental backups tar File by file backups (archives) Easy to recover selected files dd – Duplicate “raw” devices mt – Control tape devices Compression tools compress gzip

9. Backup Strategies Full Backups – Backup entire system Partial Backups – Selective backup Differential – Backup files modified since last full backup Incremental – Backup files modified since last incremental backup Snapshot versus Archive Backups

10. Data Recovery Create restore location/mount point Restore from last full backup first Restore from most recent lowest level incremental Increase level and repeat Should plan backup schedule to keep restore time manageable

11. Data Recovery Examples 0 0 0 0 5 5 5 5 5 0 3 2 5 4 5 0 9 9 5 9 9 3 9 9 5 9 9 0 3 5 9 3 5 9 Bold tapes used Restored in left to right order