Wow! This gets a lot of positive reviews, but it definitely does not work for me. The scheduled database backup works for me, both zipped and unzipped. Full Backups of a site smaller than 1GB fail whenever I try using compression. Manual full backups without compression work.
Now comes the interesting part...
Scheduled full backups (not compressed, since even manually that doesn't work) set on a once a month (beginning of the month) backup schedule creates approximately 23 folders per day, each folder containing full site backups, but never successfully completing. There are some tar files in there as well. Left this on a customer site, and they racked up over 860GB worth of data in the backup folder alone - after just 3 months of scheduled "monthly" backups. Considering again that their site is less than 1GB in size to start with, you can see the problem.
To top it off, nobody has yet to receive an email stating a successful backup as been completed for the weekly DB backups that were successful.
Hosting for this particular site is on HostGator.
Definitely would not recommend this plugin. Think I'll stick with a custom script backup via cron and S3. That works flawlessly.