Types of information

It is important to backup the information in the SKIRT project directory on a regular basis:

The repositories are hosted on GitHub where one can expect appropriate backup measures are being taken. Still, it seems prudent to make a yearly backup in a different location.
Original data, such as resources obtained from third parties and benchmark or functional test specifications, should be backed up up as soon as relevant changes were applied.
Derived data, such as resource files converted from original data or test results, can be easily regenerated, at least in principle. Still, it seems prudent to make a yearly backup.

Backup instructions

The Backup/create_backup.txt text file describes the type of information residing in each of the SKIRT project subdirectories. Whenever the structure of the SKIRT project (sub)directories changes, the contents of this file must be manually adjusted. The format of the instructions is described here: pts.admin.do.create_backup.

Creating backup archives

Using the instructions in create_backup.txt, the PTS create_backup command can be used to create ZIP archives containing a backup of all or some SKIRT project (sub)directories. For example:

$ pts create_backup --help
   ...
   optional arguments:
     -h, --help           show this help message and exit
     --derived <int>      backup derived data (specify zero to skip) (default: 1)
     --repos <int>        backup repositories (specify zero to skip) (default: 1)
     --name <str>         backup only project subdirectories starting with this name (default: )
$ pts create_backup --name ResourcesC/Publications
   Starting admin/create_backup...
   Creating backup directory: /Users/.../SKIRT/Backup/Backup--2025-07-14--11-27-06
   Creating backup for original data ResourcesC/Publications...
     Including /Users/pcamps/SKIRT/ResourcesC/Publications/Isbell2025.png
     ...
     Including /Users/pcamps/SKIRT/ResourcesC/Publications/Dubois2021.pdf
   Finished admin/create_backup.
$ pts create_backup --derived 0 --repos 0
   ...
$

The first command in this example lists the optional arguments as a reminder for the user. The second command creates a single ZIP archive including the contents of the specified subdirectory. The third and last command creates a ZIP archive for each of the (sub)directories specified as "original" in the instructions text file. In each case, the ZIP archives are placed in a Backup subdirectory with a name that includes a time stamp.

For more information, see pts.admin.do.create_backup.

Moving backups offsite

It does not make sense to leave the backup ZIP archives on your local computer because they would be vulnerable to failures such as disk crashes or physical theft. Furthermore, placing the backups in a shared location allows others to recover the data in case of an emergency or when moving responsibilities from one administrator to another. All backup ZIP archives should therefore be moved to the designated Ghent University backup server.

For more information, see Write access to the SKIRT project's online presence.