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I am using Drupal 7 site on a remote server (bluehost). I cleared the cache before the backup.

  • When I am using the backup and migrate module, and use admin -> config -> back up - the size of the file is 456 kb.
  • When I am using the my php admin interface, and Export the specific database - the size of the file is over 22 MB.
  • When I am looking at the database interface of bluehost, it's written that the same database is over 176 MB.

I know that I am missing something, but I can't figure out the answer.

What is the difference between the databases? Which one should I save?

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up vote 8 down vote accepted
  • 456kb does sound very small, maybe you don't have much content/field data? Backup and migrate will exclude data from core cache tables, and the sessions and watchdog tables (though not cache tables installed by contrib modules) by default; so that might account for it. It's also probably gzipped.
  • An export through phpmyadmin will include all those tables (and perhaps isn't gzipped), so it should be larger than the backup and migrate version
  • The size of the database on disk, on the server, isn't and can't be proportional to the size of an SQL dump file. There are indexes and other meta data which take up space, so it will almost always have a larger footprint.

You don't need the cache table data, so as soon as you've confirmed that the dump from backup and migrate has the content you need in it (always a good idea to check), you should use that one going forward.

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Thank you for the great and fast answer. I don't have a lot of content - the site is very new. what is "field data"? Can you please what is the "dump" and where is it? – EB84 Feb 20 '14 at 22:45
Sorry, by "dump" I just mean the file that you get from backup and migrate (probably a .sql, .gz or .tar.gz), as in "data dump". "Field data" is the data for fields that you may have attached to content types (the body field, image fields, other text fields, etc) – Clive Feb 20 '14 at 22:47
Backup and MIgrate will skip the data for core cache tables, watchdog, and sessions by default. Cache tables created by contrib modules will be backed up by default. – MPD Feb 20 '14 at 23:47
Thanks @MPD, I've added that in – Clive Feb 21 '14 at 1:44
Sorry I completely missed that last comment. I'd be hesitant to say it's "all you need", in theory it absolutely should be, but it's always best to do a dry run first to be absolutely sure. The worst thing in the world is a false sense of security after all :) – Clive Feb 25 '14 at 21:27

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