How to convert bzip2 file to zip file
Previous versions of BackWPup were shipped with support for bzip2 (bz2), a common algorithm used to compress files and directories. This means that in previous versions it was possible to create bz2 backup archives. In this documentation we want to explain how to convert bzip2 to zip file to make a restore with BackWPup.
The reason why the bz2 format is not anymore supported is because even if php supports this algorithm, its implementation doesn’t give the possibility to decompress large backup archives in a manner that allows us to extract the archive by chunk. So it is not possible to open the archive, extract the files and then open again the archive and extract other files. Everytime we open the archive we must read it from the beginning.
Hence we stopped to support such a format.
For this and other reasons we discourage you to use bz2 compression.
Convert bzip2 file to zip before restoring the backup
Anyway, if you have created a backup using bz2 with a previous plugin version you must convert it to .zip or .tar.gz or .gz before you start to restore it.
We suggest you to convert to .zip that is the most supported algorithm unless you don’t have ZipArchive in your server. In that case a .tar.gz could be the best solution.
To convert the bz2 file into a zip one you can use an application such as 7zip for windows or a service like cloudconvert. If you are running macOs or a linux you can take advantage of the built in support of these systems.
After you have converted the backup go to BackWPup → Restore page within the WordPress backend and upload the file.
The restore will take care of the rest.