mysqldumping my 4gb database kills server until it's done. better solution?
 

I have a mysqldump cron job that runs every day on my mid-sized forum (300 concurrent users and 4gb database).

Every time it runs, the website is inaccessible. You're lucky if a page even loads. Everyone keeps refreshing and refreshing of course, which snowballs the downtime effect. Everything's hectic until the dump is complete and things return to normal.

• If I turn vB off via the active/inactive switch in vB options, the dump takes ~8 minutes.
• If the forum isn't deactivated during the dump, the forum is down for 30min to an hour and I've had table corruption problems recently.

Question:

Here's my cron job:

Code:
mysqldump -hxx.xx.xx.xx -uusername -ppassword forumname > /home/user/backup/forumname_`/bin/date +\%Y\%m\%d`.sql.gz
Is there a backup method that is easier on the server for daily backups?

Ideally, the forum would "turn itself off" at 0500 with a "BRB, forum database is backing up" message and then the mysqldump would run, turning the forum back on when it's finished.