One of the questions I receive the most is: "What version of Plesk works with MySQL 5?" The minimum version of Plesk for MySQL 5 is 8.1.0. If you install MySQL 5 on a version prior to 8.1.0, you may be able to access then panel in the other 8.x versions, but your upgrades will fail miserably.
In case you're curious about a slightly older system, full MySQL 4 support was available in Plesk 7.5.3. However, MySQL 4 is supported on some distributions as far back as 7.1:
Fedora Core 2
Mandrake 10
SuSE 9.0
FreeBSD 5.2.1
Check out SWSoft/Parallel's site for more information about MySQL 4 and 5 support.
