Red Hat Enterprise Linux 5 Administration Unleashed

CHAPTER 10Techniques for Backupand RecoveryIN THIS CHAPTER. Writing a Backup Plan. Using Amanda for Backups. Other Linux Backup Utilities. Recovery and RepairWhen hardware components or security measures fail,every administrator must be prepared to recover a systemas quickly and efficiently as possible. Preparing for a disastermeans having a solid backup procedure and a welltestedrecovery process.Because you can’t always detect when a failure will occur, itis important to create backups on a regular basis dependingon how often the data changes and how much time ittakes to complete the backup. All the files on the systemdon’t have to be included in every backup. Consider howoften the files change. For example, operating system filessuch as files in /bin/ and “virtual” files in /proc/ and/dev/ do not need to be backed up because they can easilybe reinstalled; this also ensures they have not be compromisedif you are restoring after a security breach.For home directories that constantly change, daily or evenhourly backups might be necessary. For the payroll databaseor LDAP server, weekly backups might be sufficient.Ultimately, it is up to the system administrator or the systemadministration team to decide. Each organization has a differentset of systems, custom configurations, and a requiredlength of time in which the system must be restored.TIPRemember to test your recovery plan before a systemrecovery is needed. Finding out that your backups do notinclude all the files necessary for a successful recoverywhile you are recovering can cause more downtime thananticipated, which can mean even more loss of data,poor customer service, or a significant loss of revenue.This chapter provides you with concepts to consider whencreating a custom backup and recovery process as well asLinux tools that can be used for backup and recovery.