What is a command line I can use to back up a MySql database every single week into a file name with the date (so that it doesn't collide with previous backups)?
Also, is this a reasonable backup strategy? My database is relatively small (a complete export is only 3.2 megs right now). The churn rate is relatively low. I need to be able to get the complete DB back if something goes wrong. And it would be extra cool if there's a way that I could see the changes that occur across a time span.
You could try MySQL Replication
Replication enables data from one MySQL database server (the master) to be replicated to one or more MySQL database servers (the slaves). Replication is asynchronous - slaves need not to connected permanently to receive updates from the master. This means that updates can occur over long-distance connections and even over temporary or intermittent connections such as a dial-up service.
This way, if something goes wrong with your primary database (the master), the slave can serve as a ready-to-use replacement.
You could try something like this:
0 4 1 * * DATE=`date +%y-%m-%d`; mysqldump -u <dbuser> -p<dbpasswd> <dbname> | gzip > dbname-$DATE.sql.gz
Which will dump your database (and gzip it) on the first of each month at 4:00 AM.
Weekly backup with cron and mysqldump:
Credit goes to @timdev answer (+1) for providing the command line.
The cron syntax goes like this :
* * * * * = [minute] [hour] [day of month] [month] [day of week]
However since you wanted weekly backups, you can specify the days on which to run the backup in the third start above (day of month), to simulate the weekly interval.
0 4 1,8,15,21,28 * * DATE=`date +%y-%m-%d`; mysqldump -u <dbuser> -p<dbpasswd> <dbname> | gzip > dbname-$DATE.sql.gz
This will run it at 4:00 AM on 1st, 8th, 15th, 21st, and 28th of each month.