How can I use bash to handle sql backups? - bash

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.

Answer 2

Since you're rotating the backups daily, you could just delete all of the ones older than 3 days. Here's also how to write to a filename based on the date:
#!/bin/bash
mysqldump -uroot -ppassword forum > /root/backups/`date +%m.%d.%Y`.sql
find /root/backups -type f -ctime +3 -exec rm {} \;

Answer 3

If you just want to delete the oldest file you can add the following to your script:
ls -U1 *.sql | head -1 | xargs rm

Answer 4

well i have dedicated sql server that is having all database for my remote apache servers on aws
now what i did is made x scripts for x databased i want to have total control over each sql withour messing things up,
now what you need to do is for backup db use this script name demosql.sh
#!/bin/bash
# Database credentials
user="database user"
password="db password"
host="localhost"
db_name="database name"
# Other options
backup_path="/location/of/folder/for/sql"
date=$(date +"%d-%b-%Y")
time2=$(date +"%R")
# Set default file permissions
umask 177
# Dump database into SQL file
mysqldump --user=$user --password=$password --host=$host $db_name > $backup_path/$db_name-$date-$time2.sql
this is how i made few scripts for each db to contr
#!/bin/bash
#project name db
source $(dirname $0)/demosql.sh
then immediate after backup i want to put all of my sql in folder to sync with s3 storage like this
#!/bin/bash
s3cmd sync --skip-existing /location/ s3://folder/
also you can control script like this on cronjob with remote servers
using ssh with bash