Examples

Let’s make a backup of configuration files of all users except the user “foo”. Let’s assume that our system has unix-like style of home directories (directory “/home” contains directories of all users; configuration files begins with dot). Name of this backup will be “user-configs”.

Configuring the Archive Example

First, we need to create the file “user-configs.aa” under the “~/.config/aa/archive_specs/” directory - this is the archive specification file. The file doesn’t need to have the same name as the backup. If it does however, the option name can be left out (in this example we specified it anyway, even it is not needed).

In the path variable we specify the archive root which is the the base directory which content we want to backup.

Variables include-files and exclude-files contains list of files and directories that we want to be included or excluded respectively. In this example we specify */.* pattern because we want to include home directories of all users (such as /home/bob, /home/joe, etc.), what the first * is for. And from within those user home directories we want to include everything that begins with . (for example /home/bob/.bashrc), what the .* pattern is for. Paths specified in these variables are relative to path.

Although, yet we do not want to include all user home directories as we specified in include-files. Those directories that should not be included we put in exclude-files (“foo” in this example, which makes /home/foo excluded). If we would not want to exclude any file then the corresponding variable would be specified as exclude-files =.

Content of the “user-configs.aa” file:

# ------ begin of user-configs.aa ------
# AutoArchive's archive specification file for users configuration files
[Content]
name = user-configs
path = /home
include-files = */.*
exclude-files = foo

[Archive]
dest-dir = /mnt/backup
# ------ end of user-configs.aa ------

Backup Creation Example

Once we configured the archive we can create the backup easily with command:

aa user-configs

and in the “/mnt/backup” directory the file “user-configs.tar.gz” will be created.

Given the “user-configs.aa” example file above, the command:

aa -i user-configs

will create level 0 incremental backup – “user-configs.tar.gz” which is essentially the same as a non-incremental backup. Another execution of the same command will create level 1 backup named “user-configs.1.tar.gz” which contains only a differences from level 0. Each subsequent call will create a next level which will contain only a differences from previous.

In order to restart to level 0 again, thus create a fresh full backup, the following command can be used:

aa -i -l 0 user-configs

Note that you should remove all previously created “user-configs” backups with level higher than 0 because they are no longer valid in regards to the newly created level 0 backup. You may pass --remove-obsolete-backups option to the command above and they will be removed automatically.

Backup Keeping

We assume that all previously created backups were removed in order to demonstrate the backup keeping.

First we create a standard backup:

aa user-configs

This creates “user-configs.tar.gz” backup. Some days later let’s say, we want to create the same backup again. However we do not want to overwrite the original one. The option -k can be used to keep the original backup:

aa -k user-configs

This will rename the original backup to “user-configs.aa.tar.gz” and create the new one “user-configs.tar.gz”. If we create the same backup for the third time (still using the -k) option, “user-configs.aa.tar.gz” will be removed, “user-configs.tar.gz” will be renamed to “user-configs.aa.tar.gz” and the new “user-configs.tar.gz” will be created. So AutoArchive by default keeps single old backup when -k options is specified. To keep more, e.g. four backups we would specify --number-of-old-backups=4 alongside with -k.

Incremental backups can be kept as well. Again, we assume that all previously created backups were removed. Let’s create a few levels of incremental “user-configs” archive:

aa -i -l 0 user-configs
aa -i user-configs
aa -i user-configs
aa -i user-configs

This will create following files:

user-configs.tar.gz
user-configs.1.tar.gz
user-configs.2.tar.gz
user-configs.3.tar.gz

Then we (manually) restart to level 2 while asking to keep old backups:

aa -i -l 2 -k user-configs

After this command following files will be present:

user-configs.tar.gz
user-configs.1.tar.gz
user-configs.2.tar.gz
user-configs.2.aa.tar.gz
user-configs.3.aa.tar.gz

Let’s explain what happened. The original file “user-configs.2.tar.gz” was going to be overwritten therefore it was renamed to “user-configs.2.aa.tar.gz”. As all backup levels higher than the renamed one depends on it they have to be renamed as well. In this example “user-configs.3.tar.gz” depends on “user-configs.2.tar.gz” therefore it was renamed to “user-configs.3.aa.tar.gz”. Finally the new increment “user-configs.2.tar.gz” was created.

Listing Archives Example

Our “user-configs” archive can be listed by following command:

aa --list

Which results to the following output:

user-configs /home                    /mnt/backups               [0]/[1]/[10]

If we pass --verbose option then it shows:

Name: user-configs
Root: /home
Archiver type: targz
Destination directory: /mnt/backups
Current backup level/next/max.: [0]/[1]/[10]
Target backup level for non-full restart: [1]
Upcoming restart reason: [No restart scheduled for the next backup.]
Restart count/max.: [-]/[-]
Days since last restart/max.: [-]/[-]
Days since last full restart/max.: [-]/[-]

The archive Name is “user-configs” as configured with the name variable in the Configuring the Archive Example section. Root corresponds to the value configured with the path variable. Archiver type is “targz” which is the default. Destination directory “/mnt/backup” is configured with dest-dir variable. Current backup level/next/max. shows [0]/[1]/[10] because in the section Backup Creation Example we have created an incremental backup of level 0, so current level is 0. Next level is 1 (restarting is not enabled). Both the current and the next levels are enclosed in square brackets because incremental archiving is not enabled (it was enabled only temporarily with the -i option). Finally, the maximal backup level is 10 as it is the default. It is also shown in square brackets because restarting is not enabled; this also applies for all following values. Since no max-restart-level-size is specified the Target backup level for non-full restart is and always be 1. Obviously, no restart is scheduled as the Upcoming restart reason value is showing. Since no restart ever occurred and no value is specified for the rest of restarting options the values Restart count/max., Days since last restart/max. and Days since last full restart/max. shows only dashes.

Cleaning Orphaned Information Example

If we remove the “user-configs.aa” archive specification file then the --list will still be showing the archive with its name enclosed in square brackets (it becomes the orphaned archive):

[user-configs] ?                    .                            [0]/[?]/[10]

This is because some information is still stored in the AutoArchive’s configuration directory. It is the snapshot file created by tar when incremental backup was created. There may be more information left behind if restarting would be enabled. All of this orphaned information can be deleted with the --purge command:

aa --purge user-configs

or:

aa --purge --all

which would remove all orphaned archives.

Backup Restoration Example

Restoring Non-Incremental Backup

Let’s say we have created simple (non-incremental) backup as in the Backup Creation Example. Thus we have a file called “user-configs.tar.gz” in the “/mnt/backup” directory. As the AutoArchive does not handle restoration we will use standard GNU tar archiver.

To restore the backup to its original destination and thus replace all existing files with the ones from the backup we can use following command:

tar -xf /mnt/backup/user-configs.tar.gz -C /home

The value of the -C option (/home) is the same as the value of path variable in the “user-configs.aa”. The -C option can be left out if the destination is the current working directory (in other words you did “cd /home” earlier).

Of course the backup can be restored to any arbitrary location by replacing “/home” with some other path in the command above. This may be more safe and convenient as it does not replaces original files. The extracted backup files can be reviewed and copied to the original destination afterwards. You may also use a graphical file manager or an archive manager to browse content of the backup interactively.

Restoring Incremental Backup

Suppose we have several increments of the “user-configs” archive in the /mnt/backup directory. The content of the directory is following:

$ ls -1 /mnt/backup
-rw-r--r-- 1 root root  10M Apr 20 17:07 user-configs.tar.gz
-rw-r--r-- 1 root root   1M May 11 12:21 user-configs.1.tar.gz
-rw-r--r-- 1 root root 1.5M Jun 26 16:43 user-configs.2.tar.gz

Which means we have backup level 0, 1 and 2. To restore entire backup to the latest possible date (in this case Jun 26) we have to restore all backup levels. Similarly to the previous example the following series of commands will restore the backup to the original location replacing the original files there:

tar -xf /mnt/backup/user-configs.tar.gz -G -C /home
tar -xf /mnt/backup/user-configs.1.tar.gz -G -C /home
tar -xf /mnt/backup/user-configs.2.tar.gz -G -C /home

As in the previous example the “-C /home” can be left out (backup will be restored to the current directory) or “/home” replaced with some other path (backup will be restored to that path).