Mac OS X Time Machine backups – a need for versions

By Grant Jacobs 17/06/2011

Apple’s new Versions feature in their up-coming Mac OS X Lion. (For general readers, not hard-core geeks!)

Some time ago I wrote about backups under Mac OS X. One of the limitations I mentioned was that Time Machine drops intermediate versions:

4.2.1 The backup loses finer increments over time


Apple’s newest version of it’s operating system, Mac OS X ‘Lion’ has a new feature called Versions that for users with more modest needs may help address this.

Apple has a blurb on Versions right near the bottom of their page summarising what they claim are over 250 new features in OS X Lion.

Basically put, one solution to the loss of intermediate files in Time Machine backups is to create copies of a project (with different filenames) that represent old versions of the project you want to hang on to.

One way to implement this solution is to use existing version control software. For those will more modest needs it looks as if Apple’s Versions may do the trick.

Early reports about Versions were of ‘automated backups’ stored as versions, e.g. hourly snapshots of the document. For many people’s use this isn’t that effective in practice, as a with longer-term projects there will be distinct points in time where you consider a project has reached a defined stage, before starting out on the next stage, or trying out a variant. At those points you want to declare a new version, to be saved right then before going on.

(With regard to trying out variants: one thing versioning is good for is to take a snapshot of a point in time, letting you try something that might not pan out, but being able to safely return to the last ‘stable’ point.)

With that in mind it was good to see Apple’s summary page include:

Manual versions

You can manually create a version of a document at any time by choosing ’Save a Version’ from the File menu.

Ideally I’d like to see the manual versions have associated with them a line of text or some ‘tag’ to the version, so that it might be more readily identified later. There’s no mention of this, so you’d guess that’s not happening. (Of course, for many documents there will be a way you can include this within the document itself.)


Apple’s summary page talks about versions of a document, but what about a project? What about when more than one document hang together as a unit? I’m guessing that Apple, as they typically do, have left more complex cases to specialist software and you might still need versioning software such as subversion, git or other versioning solution[1] to attend to this.

Versioning can apply to any documents you change, including data files, art work and so on. Having a means to do this built-in with every application, to apply to any document, is a useful, pragmatic, feature.

A Finder-based solution, perhaps based around folder or smart folders, might have been a useful nod towards managing projects.

Of course, Time Machine backups are still is dominantly an on-site backup, a major limitation. You really want your backup stored at another location so that in event of thief, fire, earthquake or whatnot, so that you have a copy at an unaffected location.

For those that want further reading, my earlier post outlines more issues.

I’ll poke into some of the other announced features (and losses) of Mac OS X Lion–if I find time!–in another post.


[1] I’m not getting into which is better. Geeks (in)famously takes sides on these things and trust me there are some hot-headed debates arguments over which is better! For what little it’s worth (not very much at all) I currently favour subversion, but bear in mind that people’s wants and needs differ.

Other articles on Code for life:

Backups, part I

Time Machine backups — some ‘gotchas’

Mac OS X dreams (Mac OS X Lion appears to be bringing at least two things on my wish list)

Choosing an algorithm — benchmarking bioinformatics

A dot in space and chromosomes

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