I upgraded Virtualmin from 4.12 to 4.132, since then the incremental backups do not work anymore. They fail straight after the first server backup with the following error:
Creating backup for virtual server [HOSTNAME] .. Copying virtual server configuration .. .. done
Backing up Cron jobs .. .. none defined. Saving mail aliases .. .. done Saving mail and FTP users .. .. done Backing up all mail files .. .. none to backup Backing up mail and FTP user Cron jobs .. .. none to backup Copying Apache virtual host configuration .. .. done Copying Apache log files .. .. done Copying Logrotate configuration .. .. done Dumping MySQL database handsandfeet .. .. done Backing up Webmin ACL files .. .. done Backing up AWstats configuration file .. .. done Creating incremental TAR file of home directory ..
Failed to open /home/[host]/.incremental : Permission denied at /usr/share/webmin/web-lib-funcs.pl line 1397, line 1.
/home/[host] is owned by root, but everything inside is owned by the virtual server's user.
The full backup that runs once a week, works just fine.
Because the last incremental backup before the update worked fine, I suspect the new backup handling does not have enough privileges to handle this.