Calculate used space by databases

Question

MySQL

Such a situation: there are quotas for /home/%username% and everything works fine, the user cannot fill the entire disk with his data.

But this quota does not work on MySQL databases that are stored in /var/lib/mysql. Accordingly, the user can put a gigabyte base on the server.

How can this problem be solved? How, for example, to calculate the space occupied by user databases? Or How can they be moved to /home/%username%?

PS
/home/%username% - chroot with your environment.

Answer 1

It’s not a panacea, but what came to mind is to put the database files in / home /% username% and make symlinks to them in / var / lib / mysql
BUT you should think about what will happen to the database files when they run into a quota and the system will not give write more. This can happen quite quickly, as deleting rows does NOT delete data by default.

Answer 2

The article www.cyberciti.biz/tips/linux-unix-setting-up-mysql-database-quotas.html describes practically what cat_crash suggested above, I'm really afraid that when the database hits the quota, it might break ... So there are links in the article to other solutions to this problem. The simplest option is to call a script by cron that counts how much space the user's databases occupy and if the volume exceeds the threshold, it takes away the user's rights to CREATE and INSERT for his database, when the volume falls below the threshold, the rights are returned.