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| __Folder synchronization__ is a means to ensure two different folders at two locations hold the same data. The synchronization is usually modified by certain rules, such as directing the program to only write new files. It is most useful for multimedia files that will not benefit from compression. The reason for this is that during encoding of such media near maximal compression is usually achieved with the codec. | This document will cover three basic types of backup; Full, Incremental and Differential. |
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| __Creating an archive__ is mainly used for long-term storage, primarily of configuration files and documents. These will benefit greatly from the compression of gzip or bzip2 because the documents aren't stored in compressed formats. Since the size required on disk is much smaller than storing copies of multimedia files, users often create numerous full backups allowing them to go back and restore files from certain dates. | '''Full''' A full backup backs up all the files in the back up target. |
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| A third alternative is called __drive imaging__. Drive imaging is similar to the creation of archives, except that instead of copying just folders and files, the entire partition that is selected is backed up to an archive byte for byte. Such archives are useful, in the case of a hard drive failure, entire partitions can be restored quickly to a new hard drive and work resumed. | '''Incremental''' An incremental backup backs up all the files that have changed since the last backup. |
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| '''WARNING:''' Backups such as drive imaging work at a low level and if improperly used can result in severe data loss, especially with a command line program like dd. Ensure you understand what is being done! | '''Differential''' A differential backup is the same as an incremental except if Windows files systems are involved. In that case it is a backup that does not clear the archive bit. |
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| One final note, some file systems support __versioning__ (snapshots at time intervals), which allows you to see all changes to a file. This is a local backup, but will do nothing in the case of drive failure. See the appropriate section for a discussion. | = Recovery = |
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| {{{ note: many people consider only the backup part of this process and do nothing to verify that the backup can be restored. It is very important to test that your back process is working and that data can be recovered. }}} It is crucial that your backups be tested by restoring from them. Here are some tests you should do to ensure you can recover from a disaster: * Restore many single files * Restore an older version of a file * Restore an entire folder * Restore an entire drive and compare the checksum If you do not test you may find out that nothing was being backed up when you need to restore the files in reality. = Backup Programs = |
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| === Simple Backup Suite === Simple Backup Suite is a program designed for desktop users. Its purpose is succinctly summarized by its title, to be a simple backup suite. It is easily installed from the repositories and comes with defaults already loaded and configured. From there you can customize what directories it backs up, what it excludes, schedule it to certain times and manage old archives. This suite creates archives, keep that in mind during use. For a thorough guide to installation and general use, please see [[BackupYourSystem/SimpleBackupSuite|SimpleBackupSuite]]. === grsync === The program grsync is simply a GUI front end for the CLI utility rsync. It presents a clean yet simple interface for controlling the synchronization between two folders. It also supports multiple sessions (otherwise called profiles) and many of the commonly used basic and advanced options for modifying the synchronization. For more information see the [[https://help.ubuntu.com/community/rsync#grsync|rsync page]]. === pybackpack === This user-friendly GUI tool is well suited for desktop users, too. It's available in the ubuntu repositories. It uses rsync-backup, and the GUI is made with Python. The GUI provides a wizard for creating backup jobs (with aninclude/exclude list), and a progress bar. The backup is actually an uncompressed copy of the files and folders, with some additional data (folder rdiff-backup-data). Here's a German page about pybackpack: [[http://wiki.ubuntuusers.de/pybackpack]] |
* Simple Backup Suite - For a thorough guide to installation and general use, please see [[BackupYourSystem/SimpleBackupSuite|SimpleBackupSuite]]. * grsync - For more information see the [[https://help.ubuntu.com/community/rsync#grsync|rsync page]]. * pybackpack - Here's a German page about pybackpack: [[http://wiki.ubuntuusers.de/pybackpack]] |
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| === Creating an Archive === When backing up from the command line '''tar''' is often used. The tar command creates an archive file, which can then be further compressed by gzip or bzip2 to decrease the size it occupies on the disk. A full explanation of this command, including how to backup, restore and how to operate over a network among other things can be found at [[BackupYourSystem/TAR]]. === rsync === Rsync updates and copies the files that have changed and even then only transfers the parts of those files that have changed. That is useful for saving bandwidth when backing up over the network. For safety, transfer between two machines is done via SSH. Rsync is especially good for backing up home directories. For a full explanation, there is a separate page about [[rsync]]. As a companion, the article on [[SSH]] is worthwhile reading for those wanting to backup over a network. === dump/restore === A CLI tool used to dump (as name implies) data from a drive to another location. Useful for backups when things are really going wrong on a system, supports incremental backup and is fairly fast. For more information please see its [[http://dump.sourceforge.net/|homepage]]. A good amount of information on its operation is located within its [[man]] page, available the usual way or [[http://manpages.ubuntu.com/manpages/karmic/man8/backup_dump.8.html|online]]. |
* Creating an Archive - A full explanation of this command, including how to backup, restore and how to operate over a network among other things can be found at [[BackupYourSystem/TAR]]. * rsync - For a full explanation, there is a separate page about [[rsync]]. As a companion, the article on [[SSH]] is worthwhile reading for those wanting to backup over a network. * dump/restore - A good amount of information on its operation is located within its [[man]] page, available the usual way or [[http://manpages.ubuntu.com/manpages/karmic/man8/backup_dump.8.html|online]]. |
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| === Simple Backup Suite === [[BackupYourSystem/SimpleBackupSuite#|SimpleBackupSuite]] |
* Simple Backup Suite - [[BackupYourSystem/SimpleBackupSuite#|SimpleBackupSuite]] * Duplicity - DuplicityBackupHowto * BackupPC - [[BackupPC]] |
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| === Duplicity === DuplicityBackupHowto === BackupPC === [[BackupPC]] == Drive Imaging == [[DriveImaging|Drive Imaging]] is a complex topic, and a new article has been created for it. Please see that page for background information and instructions on how to create and restore images of folders or whole partitions. == Alternatives == === Versioning File Systems === These will be very useful when they mature. For example, ext3cow file system states it, "provides a time-shifting interface that allows a real-time and continuous view of the past. This allows users to access their file system as it appeared at any point in time." This feature is automatic -- nothing (meaning no backups, manual copies, etc.) need be done to have this benefit when using a copy-on-write file system. * [[http://www.ext3cow.com/Welcome.html|ext3cow]] (Last release: March 9, 2008) * [[http://wayback.sourceforge.net/|Wayback]] (Last release: 2004-06-26) * [[http://n0x.org/copyfs/|CopyFS]] (is unmaintained) * [[http://en.wikipedia.org/wiki/Btrfs|B-tree FS]] (not yet stable - April 2010) * [[http://en.wikipedia.org/wiki/ZFS|ZFS]] (no native filesystem in ubuntu) They let you see ''every'' change to a file over its life span, but offer no protection against a hard drive that fails. These projects are therefore complimentary to the backups described above, which offer snapshots or synchronization that can be stored on other hard drives or even other locations on a network. Versioning tools such as [[Subversion]] could also be useful while we wait for versioning file systems to become mature and fully supported. |
= Alternatives = |
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| [[http://pietrobattiston.it/wiki/doku.php?id=comparison_of_backup_softwares|A comparison of graphical backup tools for Linux desktop.]] | |
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| Other wiki discussing various Linux backup techniques: * [[http://www.nslu2-linux.org/wiki/HowTo/BackupYourLinuxBox|NSLU2: back up your Linux box]] See the full discussion in these threads on the Ubuntu forums: * http://ubuntuforums.org/showthread.php?t=868244 * http://www.ubuntuforums.org/showthread.php?t=70566 * http://www.ubuntuforums.org/showthread.php?t=35087 Howto: Backup and restore your system! (very long thread; but all the good bits have (hopefully) already been summarized on this page.) * http://ubuntuforums.org/showthread.php?t=295 [[http://www.debianadmin.com/backup-and-restore-your-ubuntu-system-using-sbackup.html|"Backup and Restore Your Ubuntu System using Sbackup"]] has nice step-by-step instructions (with screenshots) of using sbackup. A personal blog listing many open source backup solutions: [[http://davestechshop.net/ListOfFreeOpenSourceLinuxUbuntuBackupSoftware|List of Free Open Source Linux and Ubuntu Backup Software]] = Recovery = {{{ note: many people consider only the backup part of this process and do nothing to verify that the backup can be restored. It is very important to test that your back process is working and that data can be recovered. }}} |
Introduction
Backup and recovery is essential. Failure to have verified backup and recovery procedures puts your data at risk of loss. Users often only learn this lesson after critical information they require is permanently lost. Attempting to recover from such data loss can be both time consuming and extremely difficult. So learn from others mistakes, and ensure beforehand that you have a system in place that protects your data and suits your needs.
Before deciding on a backup and recovery strategy you have to ask the following questions:
Why? - Why are protecting yourself against disaster? Does it matter if you loose data? What loses will you suffer ($$$)?
What? - What are you going to backup? Your entire hard drive or just some of the data?
When? - When is the best time to backup your system? How often will you perform a backup? When will you use full backups and incremental backups.
Where? - Where will the backups be stored? On-site? Off-Site? Cloud?
Medium? - Attached storage (usb stick, usb hard drive, tape drive), backup server?
Backup
Types of Backup
There are many methods to provide backup and recovery; choosing the best process for you or your business will have to take several factors in to account.
- Recovery time objective: How fast should data be recovered? Can you continue to operate if data recovery is not recovered for a day, a week, etc?
- Recovery point objective: How much data can be lost. Can you lose two hours, two days or two weeks of data?
example: if you can withstand losing one week of data then a weekly backup would be sufficient, but if you can only withstand losing one day then you would need to employ a nightly backup (or a variation)
This document will cover three basic types of backup; Full, Incremental and Differential.
Full A full backup backs up all the files in the back up target.
Incremental An incremental backup backs up all the files that have changed since the last backup.
Differential A differential backup is the same as an incremental except if Windows files systems are involved. In that case it is a backup that does not clear the archive bit.
Recovery
note: many people consider only the backup part of this process and do nothing to verify that the backup can be restored. It is very important to test that your back process is working and that data can be recovered.
It is crucial that your backups be tested by restoring from them. Here are some tests you should do to ensure you can recover from a disaster:
- Restore many single files
- Restore an older version of a file
- Restore an entire folder
- Restore an entire drive and compare the checksum
If you do not test you may find out that nothing was being backed up when you need to restore the files in reality.
Backup Programs
Backup From a Graphical User Interface
GUIs offer a graphical interface from which a user can choose from a limited selection of options to customize operation. There are also usually configured defaults and guides that help in selecting the right options. There are a few to choose from, below you'll find several good choices that work well.
Simple Backup Suite - For a thorough guide to installation and general use, please see SimpleBackupSuite.
grsync - For more information see the rsync page.
pybackpack - Here's a German page about pybackpack: http://wiki.ubuntuusers.de/pybackpack
Backup From the Command Line
CLI's primary advantage over a GUI is that it exposes directly to you many more options. With that however comes the obligation of knowing exactly before hand what you want to do. There are no defaults with commands it's entirely up to the user to set the desired options. To better acquaint yourself beforehand, it is advisable that you read UsingTheTerminal.
Creating an Archive - A full explanation of this command, including how to backup, restore and how to operate over a network among other things can be found at BackupYourSystem/TAR.
rsync - For a full explanation, there is a separate page about rsync. As a companion, the article on SSH is worthwhile reading for those wanting to backup over a network.
dump/restore - A good amount of information on its operation is located within its man page, available the usual way or online.
Backup Destination on a Remote Machine
Simple Backup Suite - SimpleBackupSuite
Duplicity - DuplicityBackupHowto
BackupPC - BackupPC
Alternatives
Early Stage Ideas
In addition to that already discussed, there are projects still in development that you may wish to keep appraised of or even participate in.
Related Links
You might also want to check out these backup programs which will help you to make automated backups of your system: