I have used R1Soft with very positive results for both MSSQL and Exchange server, it will also support MySQL, in fact they are very good with database backup. It is very fast and supports continuous data protection, running backup every hour. Each backup is a full backup and is also an image for bare metal restore. It works great with both Linux and Windows and have a great web interface, can send your backup to secondary location and much more. Only thing I miss is deduplication, but the say it will come in the future.
Compared with many other Enterprise backup solutions it is also very cheap. Can’t remember the price, but it was something like 10$ pr. server. You can use your own storage or rent a storage place.
Link:
http://www.r1soft.com/
For Open Source solution I have looked at Borg backup, a fork of Attic backup. I looks VERY promising but you need to write your own scripts and it is manly only for Linux.
Link:
https://borgbackup.readthedocs.org
Or you could look at Urbackup, another Open Source solution. It also looks very promising for both Linux and Windows with image backup for Windows. It have a strange looking web interface, but the new version that is soon to be released have a more modern look. It is also more in the Enterprise direction.
Link:
http://www.urbackup.org
But I am always looking for the best backup solution, so if anyone else have better backup solutions, especial Open Source solutions, I am all ears...