Developing backup software for backing up LVM volumes (linux)

We need a backup solution to backup multiple of our servers. The servers are hypervisors and we need to backup LVM volumes (using the snapshot technology). We currently have a backup solution in place but it doesn't meet our standards (more insight on this can be given if you are hired). So basically, we have one backup server (however the software you write should be able to be scale, so adding multiple backup servers should be possible) which backs up the LVM volumes on multiple servers. We require the software to have an API so we can create a frontend for the software and integrate it in our website. The backup software should be able to do the following: * backup at specific times per server (so backupserver1 backs up server1 at 00:00, backupserver2 starts backing up server2 at 00:30 etcetera) * you should be able to create a very basic web interface to manage the backups (restore / restore to different server (and different lvm volume) / delete) * should be able to restore the backup through the API * create a full backup each per X days (7 as default, unless otherwise stated), the other days create an incremental * the software should be bulletproof, reattempt to backup when failed and send an email when the backup has failed * on-demand backups, so every LVM volume can be backed up / restored whenever you want (with a limited "on-demand backup slots") - more information on this can be given when you are hired We will provide you with test servers (3 clients and 2 backup servers - all running on CentOS) where you can test / develop your software on.