Backup strategy needs overhaul

[ebreton]

Only one incremental tar has a lower weight in the list below (on the 7th of January):

-rw-r--r--. 1 www-data www-data    70735 Jan  9 00:05 demohd_20180103000535.list
-rw-r--r--. 1 www-data www-data    82624 Jan  3 00:05 demohd_20180103000535_full.sql
-rw-r--r--. 1 www-data www-data 37621760 Jan  3 00:05 demohd_20180103000535_full.tar
-rw-r--r--. 1 www-data www-data    83625 Jan  4 00:05 demohd_20180104000544_inc.sql
-rw-r--r--. 1 www-data www-data 37621760 Jan  4 00:05 demohd_20180104000544_inc.tar
-rw-r--r--. 1 www-data www-data    82624 Jan  5 00:05 demohd_20180105000531_inc.sql
-rw-r--r--. 1 www-data www-data 37621760 Jan  5 00:05 demohd_20180105000531_inc.tar
-rw-r--r--. 1 www-data www-data    83625 Jan  6 00:05 demohd_20180106000513_inc.sql
-rw-r--r--. 1 www-data www-data   266240 Jan  6 00:05 demohd_20180106000513_inc.tar
-rw-r--r--. 1 www-data www-data    78844 Jan  7 00:05 demohd_20180107000538_inc.sql
-rw-r--r--. 1 www-data www-data 37621760 Jan  7 00:05 demohd_20180107000538_inc.tar
-rw-r--r--. 1 www-data www-data    78844 Jan  8 00:05 demohd_20180108000526_inc.sql
-rw-r--r--. 1 www-data www-data 37621760 Jan  8 00:05 demohd_20180108000526_inc.tar
-rw-r--r--. 1 www-data www-data    79845 Jan  9 00:05 demohd_20180109000536_inc.sql
-rw-r--r--. 1 www-data www-data 37621760 Jan  9 00:05 demohd_20180109000536_inc.tar

[domq]

Also, we have no backups on the test platform and since we use it to host validation instances that are user-mutable, we have already lost data that way.

Incremental backup with tar is a bit 1970's. We should investigate tools such as rdiff-backup or bup