I want to backup all of the MySQL databases on my server on a routine basis.
As I started asking how to get a list of all databases in MySQL on Stack Overflow, I came across this previous SO question, entitled, “Drop All Databases in MySQL” (the best answer for which, in turn, republished the kernel from this blog post). Thinking that sounded promising, I opened it and found this little gem:
mysql -uroot -ppassword -e "show databases" | grep -v Database | grep -v mysql| grep -v information_schema| |gawk '{print "drop database " $1 ";select sleep(0.1);"}' | mysql -uroot -ppassword
That will drop all databases. No doubt about it. But that’s not what I want to so, so I edited the leading command down to this:
`mysql -uroot -e "show databases" | grep -v Database | grep -v mysql| grep -v information_schema| grep -v test | grep -v OLD | grep -v performance_schema
Which gives back a list of all the databases created by a user.
Now I need a place to keep the dumps .. /tmp sounded good.
And each database should be in its own file, for I need mysqldump $db.identifier.extension
Made the ‘identifier’ the output of date +%s to get seconds since the Unix epoch (which is plenty unique enough for me).
All of which adds up to this one-liner:
for db in `mysql -uroot -e "show databases" | grep -v Database | grep -v mysql| grep -v information_schema| grep -v test | grep -v OLD | grep -v performance_schema`; do mysqldump $db > /tmp/$db.dump.`date +%s`.sql; done
Plop that puppy in root’s crontab on a good schedule for you, and you have a hand-free method to backup databases.
Thought about using xargs, but I couldn’t come up with a quick/easy way to uniquely identify each file in the corresponding output.
Might consider adding some compression and/or a better place for dumps to live and/or cleaning-up ‘old’ ones (however you want to determine that), but it’s a healthy start.
You can also do mysqldump --all-databases if you think you want to restore all of them simultaneously … I like the idea of individually dumping them for individual restoration / migration / etc.
The full script I am using (which does include backups, etc):
############################
#!/bin/bash
date
echo 'Archiving old database backups'
tar zcf mysql-dbs.`date +%s`.tar.gz ~/sqlbackups
rm -f ~/sqlbackups/*
date
echo 'Backing up MySQL / MariaDB databases'
for db in `mysql -uroot -e "show databases" | grep -v Database | grep -v mysql| grep -v information_schema| grep -v test | grep -v OLD | grep -v performance_schema`; do mysqldump $db > ~/sqlbackups/$db.dump.`date +%s`.sql; done
echo 'Done with backups. Files can be found in ~/sqlbackups'
date
