BackUps?

As far as I understand it, mysql simply won't accept it, the database MUST be unplugged entirely for the database backup to proceed. No way around it at all.

But that's all, for the rest, the websites are supposed to work. I've seen super huge (talking over 50 GB, taking a long time) websites backed up flawlessly and still being served to the internet while virtualmin was patiently making a tarball copy of its file contents.

Howdy,

Hmm, no service should go offline during backups.

Virtualmin uses the mysqldump tool to generate database backups -- MySQL isn't taken offline, and the websites aren't disabled.

There may be a brief period while running mysqldump on a given database where the rows are locked in order to protect the integrity of the data... but that should be very brief, and most people wouldn't even notice it (as it should only affect writes, not reads).

So it sounds like something else might be going on.

You may want to review the resource usage on your server to see if maybe the load is getting high during the backup process. If there's a high CPU load, that could make it look like the sites aren't responding.

-Eric