Is your feature request related to a problem? Please describe.
In https://github.com/glpi-project/glpi/pull/7183 database backup was droped, because it was very slow and works only for very small databases.
Describe the solution you'd like
I think it will be good to use https://github.com/ifsnop/mysqldump-php or system
mysqldump to dump database.
Describe alternatives you've considered
Alternatively the backup task can be triggered by cron job with tools mentioned above.
1. User clicks backup button in web ui.
2. Automatic action for cli created.
3. Cron triggers backup job.
4. Backup starts in cli process.
Customer support service by UserEcho