Question

I have a database and I used to backup daily manually like so

 mysqldump -uroot -ppassword forum > 4.25.2011.sql

However I’ve been doing the above and wanted to use a script besides mysqldumper to do the job.

If 3 existing .sql files exist in the backup directory, how can I delete the oldest one?

So far all I have is:

#!/bin/bash
today = `eval date +%m.%d.%Y` #how do I add this to the backup?
mysqldump -uroot -ppassword forum > /root/backups/4.25.2011.sql

I still can’t figure out how to pass a variable to save my sql file as. How would I do that too?
My VPS is limited to 10gb and disk size is a concern or else I wouldn’t delete any files.

Answer 1

For your first part, instead of

today = `eval date +%m.%d.%Y` #how do I add this to the backup?
mysqldump -uroot -ppassword forum > /root/backups/4.25.2011.sql

do

today=$(date +%m.%d.%Y)
mysqldump -uroot -ppassword forum > /root/backups/$today.sql

In particular:

• there must not be any spaces around the equals sign
• running eval is not what you want

The simplest way to only keep three files would be:

rm forum-3.sql
mv /root/backups/forum-2.sql /root/backups/forum-3.sql
mv /root/backups/forum-1.sql /root/backups/forum-2.sql
mysqldump -uroot -ppassword forum > /root/backups/forum-1.sql

Tools like ls -l or the content of the file should tell you the date if you need it.

If you really need the date in the file name, the easiest tool to help you is GNU date:

dateformat="%m.%d.%Y"
rm forum-$(date -d "-3 days" +$dateformat).sql
mysqldump -uroot -ppassword forum > /root/backups/forum-$(date +$dateformat).sql

Or use find, e.g.

find . -name "forum*.sql" -mtime +3 -delete
mysqldump -uroot -ppassword forum > /root/backups/forum-$(date +$dateformat).sql

After that, you could look at logrotate.