Linux - Part 21
Although I use Linux most of the time, when it
comes to full-system backups, I have resorted to dual-booting into
Windows and using the free edition of Macrium Reflect (http://opcug.ca/Reviews/ MacriumReflectFree.htm). Under Linux, I have so far restricted my
backups to either file and folder synchronization using FreeFileSync (http://opcug.ca/Reviews/linux_part18.htm), or real-time backup of my data partition
using inosync (http://opcug.ca/Reviews/linux_part16.htm). Now, it's time to move on and find a more
comprehensive Linux solution for file, folder, and disk partition
One program that I have tried in the distant past is partimage (http://www.partimage.org/Main_Page). A brief return to this software reminded me
that it sports a quasi-graphical interface (much like old DOS
programs), needs to be run as root, and requires partitions to be
unmounted for processing. The simplest way around all of these issues
is to run the program using a bash script file.
My solution was to incorporate commands to unmount my data partition
(sudo umount /dev/sda2), run partimage, and then remount the data drive
(sudo mount /media/DataDisk/) to make this once again available for
use. The command to run partimage to make the backup on my external USB
drive (/media/MYBOOK1) takes the form:
sudo partimage -z1 -o -d -b -B=alan save
The switches used for partimage are mostly straightforward: -z1=use
Gzip compression, -o=overwrite any existing image file, -d=no
description, and -b=run in batch mode (GUI doesn't wait for input). The
-B switch is a little strange. There has to be a -B=value, but
partimage doesn't seem to care what “value” is used. I opted to use
-B=alan which worked just fine.
The other potential problems with partimage are that it has no support
for the ext4 file system and there is no 64-bit version of the
software. A possible workaround for both these issues is a relatively
new program named fsarchiver (http://www.fsarchiver.org) for file
system archiver. However, a possible downside to fsarchiver is that,
while it also supports NTFS, it has no support for FAT disk volumes.
This program is a bit similar to partimage (although it currently only
sports a command line and no GUI) and at least one web posting suggests
that the two pieces of software may come from the same programmer.
Fsarchiver uses a slightly different command line format than
partimage. It's still best to work with unmounted volumes, but I was
easily able to get my bash script file to work by modifying the main
sudo fsarchiver -o -v savefs
The -o switch is to overwrite any existing backup file, while the -v
switch provides verbose output and displays the progress for individual
files while the backup process is running.
Fsarchiver provides support for multiple file system backups in a
single file system archive (.fsa) file. While perhaps an interesting
idea for some, for me this has the disadvantage that it is even more
difficult to retrieve individual files or folders from the backup. So,
onto yet another possible backup solution...
The current release of Ubuntu Linux (Oneiric Ocelot) has the Déjà Dup (https://launchpad.net/deja-dup) backup utility built into the distro. If you
are a fan of minimal graphical user interfaces, then you have arrived
at the right place! Launching Déjà Dup produces a small window with two
large buttons – Backup and Restore – so, it's not too difficult to
figure out how the program works.
Setting the program's preferences to indicate
the backup location, and the files and folders to be included in the
backup process, is a straightforward process. The dialogue box has a
number of other options, such as the ability to add a list of
exceptions for files or folders that are not to be included in the
backup, file encryption, backup on a regular schedule (e.g. daily), and
setting the time period for which backups should be retained (which
Déjà Dup is actually a graphical front end to a program named
duplicity, and it's the latter utility that creates the backup,
essentially as a series of Gzip files. Initially, duplicity makes a
complete backup of the source files. Subsequent backups are made as a
series of incremental backups such that only the changes in the source
files are copied to the target directory.
The backup series is stored chronologically in a bewildering series of
volumes, manifests, and signature files in the target directory.
Fortunately, these are effectively transparent to the user. Pressing
the Restore button returns a “Restore from When?” dialogue box, with
the individual backups in the series being displayed in a simple list.
Running the program to create or restore an entire backup is as simple
as pressing a button. The only real downside is that recovering a
single file from the backup set is not a straightforward exercise.
There is no option for this built into the program, and finding a given
file among the many Gzip files is probably more trouble than it's worth.
Several backup packages available for Linux are based on the rsync file
synchronization utility. This program creates backups by simply copying
files, which makes restoring a single file or folder very easy. Some
time ago, I played around with rsync (http://opcug.ca/Reviews/ linux_part9.htm), but found the use of the command line
tedious. While one can use a bash script file to make the backup
process more efficient, it's even simpler to use a purpose-built backup
program that essentially adds a graphical front end to the package.
Next time, we will review some packages that use this technique.
published: March, 2012
expressed in these reviews
do not necessarily represent the views of the
Ottawa PC Users' Group or its members.