# For Maximum Safety, Copy Everything

The *safest* option is to *copy everything*, including invisible meta-data files.

Files tend to exist for a reason and as software changes, so will the existence, purpose, and contents of these meta-data files. Copying everything will reduce the maintenance burden and offer ease of mind that nothing is being lost.

The log file created by `rsync` will be technically involved by the very nature of `rsync` being a command line tool. Consider presenting a tidied up, meta-data filtered, and maybe even coloured coded output for the user to check. You could do this with a wide range of scripting tools and languages. Please ask more questions here on [Ask Different](https://apple.stackexchange.com) and on [StackOverflow](https://www.stackoverflow.com) if you need help with this approach.

## Delete Last & Copy OS X Resources

Regarding the `rsync` flags, take a look at the question http://apple.stackexchange.com/questions/117465/fastest-and-safest-way-to-copy-massive-data-from-one-external-drive-to-another/117469#117469. In this question, a few additional flags are used and explained:

    sudo rsync -vaE --progress --delete-after /Volumes/SourceName /Volumes/DestinationName

In this situation, the `E` will ensure resource forks and other Mac specific properties are copied.

You may want to consider `--delete-after` to avoid deleting until the copy has completed; please note that this approach will potentially require a destination drive twice the size of the source.

# Possible Exclusions

An answer to a related question, http://apple.stackexchange.com/questions/85778/how-can-i-omit-fcpx-render-files-from-a-time-machine-backup, provided a useful link of [OS X files and folders that can be excluded from most back-ups](https://bombich.com/kb/ccc4/some-files-and-folders-are-automatically-excluded-from-backup-task). This link provides a practical list of file patterns, folders, and paths that you could exclude.

## Include dot Files

There are good reasons to back up files beginning with dots, `.*` matching files.

Some software keeps preferences, settings, and other information of value in folders at the top of the user's folder in invisible dot prefixed folders. Running `ls -la ~/` will reveal these folders and files.

If any user uses or has software that in turn uses version control software, be sure to back-up dot files. Software like [subversion][1] and [git][2] both store critical information within their dot folders. These hidden folders can be scattered across your file system, where ever a project is checked out.

# Spotlight and Disk Access

Spotlight is OS X's search service. Spotlight uses the `mdworker` process to index and update the search catalogue. If you are concerned about possible disk corruption or slow copies, [disabling `mdworker`](http://osxdaily.com/2009/09/14/mdworker-what-is-mdworker/) while running `rsync` may help. Personally, I leave Spotlight running while running large `rsync` transfers.

  [1]: https://subversion.apache.org
  [2]: http://www.git-scm.com