MySQL Hotbackups with XtraBackup
Nov 16, 2010, 18:34 (0 Talkback[s])
(Other stories by Sean Hull)
"Relational Databases typically have a lot in common in terms of
backups. They have different names for things, but they boil down
to the same thing.
"First, you have logical backups. These are also known by the
name database dumps, or exports. What are they? When you perform a
logical backup, the database engine digs through your database, to
create all the statements required to build it again. Think of it
as the instructions to build the building, not the building itself.
Like an architect's drawing. These instructions can be fed into the
database engine at a later time, to rebuild everything from
scratch. Inside a logical backup, you'll find statements like
CREATE DATABASE, CREATE TABLE, CREATE VIEW, INSERT, and so on.
"Next, we have cold backups. These are created by first shutting
down the database and stopping all the software that mounts the
physical files. When it is not running, your database sits in
datafiles on the filesystem. A cold backup is then made by making
copies of all of these files, then tar & compressing them in
the backup directory. Therefore, to restore from a cold backup,
unlike a logical backup, no rebuilding needs to happen, and no SQL
statements need to run. You simple need to configure your database
software to point to the restored files, and start it up!"