vBdatabase corrupt last night - Looking for Cron to turn off forums during Backups

[Quarterbore]

I had my first database meltdown (that was not my fault) and I spent quite a bit of time going through my access logs, error logs, and ftp logs and it looks like the problem was three Bots just pounding my server last night (Snapbot, YAHOO BOT, and GOOGLE Bot). It looks like Snapbot was the worst hitting filese no more then a second or two apart but what seems to have caused me harm was that all three bots were chomping at my data when my Server based CRON job tried to do a MYSQLDUMP of my data...

When I woke up this morning my database wehnt from 33MB to 310 bites (NO DATA).

So, what I want to do is create a small cron that will turn off my forums during my slowest time (about 2:30AM EST). Then I will set my server based CRON to backup the database at about 2:35AM EST. Finally I plan to turn the server back on again at 2:45AM EST (Assuming 10-minutes is adequate for the server based dump)

Is this rational or am I just knee jerk reacting to losing my database? I already do daily backups with archive copies of 2-backups a week that never get deleted but it just really frustrates members to lose their data even if it is just one days worth....

If it is a sound idea, does anybody have information on how I can write a script to turn the database off and by the obvious, a second script to turn it back on? I am using vB 3.5.3.