Lecture #10   Backup and Restore

Learner Outcomes

• Choose an appropriate backup strategy given a set of requirements
• Perform full, incremental and differential backups
• Restore a system from one or more backup archives
• Describe the issues around pathnames and symbolic links with respect to backups.

Agenda

1. Overview of Backup Strategies
2. Exercises 9.3 from the back of the chapter.
3. Demonstration of the tar, cpio, and dump commands.
4. Backup -> Disaster -> Restore

Assignment

1. Read Chapters 5 and 9
2. Do Lab 8
3. Extra Credit lab8x

Resources

• PowerPoint Slides
• Lecture 10 Archive

System Backup and Restore

1. The Backup Process
   • Backup Policies
   • Devices
   • Problems with Backup Programs
   • Restoring Data
   • File Permissions, Types, and Structures
   • Defragmentation
   • Protecting the Backup Media
   
   
2. Backup Devices
   • Tape Devices
     • Problems with tapes
     • The buffer utility
     • Tapes and random file access
   • Writable CD and DVD
     • Limits of optical media
   • Other Removable Media Devices
   • RAID Arrays
   
   
3. Types of Data
   • System Data
     • Basic information to set and run the system
   • Application Software
     • Best to reinstall from source installation disks
   • Databases
     • Most important data types
   • User Data
     • Includes site work
   • User Data and Home Directories
     • Includes e-mail, files from home directory for personal use
   
   
4. Methodologies
   • Epoch
     • Arbitrary time interval that denotes a beginning
     • Beginning of backup process
   • Incremental
     • All files that have been added or changed since epoch
   • Differential
     • Similar but easier than incremental, only uses two tapes
   • File Ghosting
     • Anomaly of the backup and restoration process
   
   
5. Archive Utilities
   • dump/restore
     • Oldest and most trusted backup utility
     • Searches for new or changed files and writes them to device
   • tar
     • Used to archive or backup files, directories, hard disks
   • cpio
     • Copy input/output
     • tar files and archives can be used without unarchiving
   
   
6. Compression Utilities
   • compress
     • Traditional compression utility
   • zip
     • Used for compressing, archiving files into single archive
   • gzip
     • Used for compressing, uncompressing files one at a time
   • bzip2
     • New, slower, but better compression device
   
   
7. Backup Software Packages
   • AMANDA
     • AMANDA's features
     • Installation
     • AMANDA's administration
     • Additional resources
   • Kbackup
     • Scheduling operations
     • MULTIBUF
     • Creating a backup
     • Restoring backups
   • Bacula
     • available under an open source license
     • backs up UNIX, Linux, and Windows systems
     • supports MySQL for back-end database
     • verifies backup jobs
     • centralizes backup management for an entire network
   • UNiBack
   • Taper
   • Arkeia

Relevant Commands and Files