Lecture #11   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.

Activities

1. Take Quiz 4
2. Exercises 9.3 from the back of the chapter.
3. Demonstration of the tar, cpio, and dump commands.
4. Exercise: Perform a full system backup
   1. Create a backup device of 3.5 GB as /dev/hda7
   2. At runlevel 1 backup all directories under / except /proc and /sys
   3. After the backup, remove all files in and below /boot
   4. Restore the /boot directory and insure that your system still boots.
5. Demonstrate dumping and restoring file systems: CCC Confer Video

Assignment

1. Do Lab 8
2. Read Chapter 8 and sections 1, 2, and 4 of Chapter 10

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