Plesk Panel Upgrading...

[NeuroPsyche]

It has become apparent that during upgrades of Plesk that certain files and databases become corrupt.
This has happened in almost every significant release that I've upgraded from.

I'd like to pose a question to all...
During the upgrade procedures using the Auto-Installer/Upgrade, does it lock/protect files that may be open?
For example: Customers online modifying their sites, users online view sites, databases open/active?

So.. with this question posed, could the corruption of files/databases be happening because the auto-upgrade program does not lock/protect files from the upgrade process and should possibly services be stopped during upgrades to prevent issues?

Thanks!

David