backup - Is copying the /var/lib/mysql directory a good alternative to mysqldump?

Question

Since I'm making a full backup of my entire debian system, I was thinking if having a copy of /var/lib/mysql directory is a viable alternative to dumping tables with mysqldump.

• are all informations needed contained in that directory?
• can single tables be imported in another mysql?
• can there be problems while restoring those files on a (probably slightly) different mysql server version?

Answer 1

• Yes
• Yes if the table is using the MyISAM (default) engine. Not if it's using InnoDB.
• Probably not, and if there is, you just need to execute mysql_upgrade to fix them

To avoid getting databases in a inconsistent state, you can either shutdown MySQL or use LOCK TABLES and then FLUSH TABLES before the backup. The second solution is a little better because the MySQL server will remain available during the backup (albeit read only).