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Comments on: Question 65: Consistency of a backup http://mysql-qotd.casperia.net/archives/460 mysql 5.0/5.1 questions for learning purposes Fri, 06 Aug 2010 16:56:36 +0000 http://wordpress.org/?v=abc hourly 1 By: plogi http://mysql-qotd.casperia.net/archives/460/comment-page-1#comment-74 plogi Fri, 11 Jun 2010 19:45:27 +0000 http://mysql-qotd.casperia.net/?p=460#comment-74 <b> a c An operating system level backup is usually not enough in order to serve as a db-backup. One exception is, if the database is shut down at the time of the backup. Normally, a consistent backup needs some special handling in the database, for example doing a "flush tables with read lock;" before copying the files and a "unlock tables;" afterwards. I've seen many companies that only had an OS level backup. And with Mysql, unlike virtually all other databases, even such a backup can be of help, if you only have MyIsam tables: You can restore those files from the backup and try a "repair table" - you'll be able to get data back, even tho all tables will be from a different point in time. </b>
a c

An operating system level backup is usually not enough in order to serve as a db-backup.
One exception is, if the database is shut down at the time of the backup.
Normally, a consistent backup needs some special handling in the database, for example doing a “flush tables with read lock;” before copying the files and a “unlock tables;” afterwards.

I’ve seen many companies that only had an OS level backup. And with Mysql, unlike virtually all other databases, even such a backup can be of help, if you only have MyIsam tables: You can restore those files from the backup and try a “repair table” – you’ll be able to get data back, even tho all tables will be from a different point in time.

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