Where exactly are old versions of files stored on the harddisk?

Here's your answer (I think)

http://arstechnica.com/apple/reviews/2011/07/mac-os-x-10-7.ars/14

Right at the top - Document Revisions.

Took a bit of tracking down but that's the best external article I can find for you right now.

Regards,

Colin R.

There's a hidden folder named .DocumentRevisions-V100 in the root directory. This is where the old versions were stored. This is a very bad, short sighted or just stupid design. So you just found another unusable feature in Lion...

"This is a very bad, short sighted or just stupid design." Why? and why is versions unusable?

coocooforcocoapuffs wrote:

yep, ur right. my dream of distributing versions of documents all in one file are dashed. When you copy a versioned document to another machine you get this:

even copying to a different directory on the same machine I lose the version information in the copy

create a multiversion rtf on the desktop, close textedit, then right click and copy that rtf to the documents folder. No versions get carried with it.

so not only do some folks like me have the hassle of dealing with versioning when I dont want or need it, folks who do have uses for it might be in for an unexpected surprise if they decide to do a bit of copy n delete sub directory housekeeping, and expect the versioning info to be carried accross.

AndreasSt wrote:

There's a hidden folder named .DocumentRevisions-V100 in the root directory. This is where the old versions were stored. This is a very bad, short sighted or just stupid design. So you just found another unusable feature in Lion...

cheers for that explains why the files will show the correct file size for the content currently 'active' within them, while ignoring the inactive content 'versioned' in them. Makes more sense than apples description of it being 'stored within the file'

..but still leaves the problem of not letting the user see exactly whats taking up space on their HDD 😟

Get to a low HDD space situation and no amount of checking file sizes is going to do any good if they have bundles of files bloated through hidden revision that's not reflected in their declared file sizes..

mrjazzycharon wrote:

Thank you! 🙂

Mr. Charon, a.k.a Jazzy: you're welcome and thanks for the credit.

Although quite long (19 pages I recall correctly) the Arstechnica review quoted by Colin Robinson is a must read for people like you (and me).

I agree to some extent with AndreasSt comments on the way this has been implemented, but I think versions is a great enhancement, although in its infancy. This is the way Apple is going: it becomes less important and more obscure where and how the actual data are stored, as long as the data. Don't know if you use Aperture or iPhoto, but the concept is, although completely differently implemented, quite the same. For control freaks like you and me something we have to adjust to.

holy crap, the more you look into this, the more my bubble is blown. ok, so i was all wet on the timemachine code theory (thx for tip on SQLlite via root, but if you can't move the file, then huh?

it's true, just moving the file trashes the revisions! so i can't chronosync my .pages to my laptop to take on the road to do my editing, and still retain the versions?!?

useless. or did I miss something?

coocooforcocoapuffs wrote:

holy crap, the more you look into this, the more my bubble is blown. ok, so i was all wet on the timemachine code theory (thx for tip on SQLlite via root, but if you can't move the file, then huh?

it's true, just moving the file trashes the revisions! so i can't chronosync my .pages to my laptop to take on the road to do my editing, and still retain the versions?!?

useless. or did I miss something?

No, it's not useless, but it has quite a few restrictions. As I said: "I think versions is a great enhancement, although in its infancy".

The Chronosync question is a good one, as I use it as well to sync data between my iMac, MBA and MBP. No way bring previous versions along if you do a bidirectional synchronization. Chronosync brings over only the latest version. Do not try to sync the hidden folder using bidirectional synchronization.

EVO67 wrote:

No, it's not useless, but it has quite a few restrictions. As I said: "I think versions is a great enhancement, although in its infancy".

At least for me it is useless. Maybe this feature is usefull for a novice user and for shure it is "cloud-friendly", but it's not usefull for everyone especialy not for professionals. It might have been ok if the old versions were stored in place with the original file. The current implementation is a backup of the old versions, implying they were not important as the original file. This is critical in combination with the "auto-save" feature. So you might change something that cannot be undone. To avoid this, the user must change his workflow. I don't think that forcing the users do that is a wise idea. Many of them still have to use Windows in parallel. Same stupid idea was to change the scrolling direction per default. This makes sense for trackpads but not for mice...

thks for checking me, I almost had a fit and reverted to Panther! Seriously, I'm glad we figured this out before I got serious about depending on it. Chronosync does something interesting, it actually locks the files when it brings them over to the target, forcing you to make a duplicate if you want to edit. But bringing back the duplicate (from the target to the host) I can edit freely. Mind boggling. I don't know if that's normal, or just my setup(s).

Curious about ur warning on the hidden folder...assuming u mean the one under root. I actually thought about trying that, as all my documents are chronosynced by schedule everynite, bidirectionally, and are all in the same dir structure.That way, whatever machine I hop on for the day, I have the latest without thinking about it. Interested to see what happens now... Cheers!

It's good advice to not attempt direct access to the data that is used by Lion for versioning.

For those of you with concerns about free space on disk: I believe that deltas are used.

Data related to Apple versions is
sometimes not limited to
/.DocumentRevisions-V100

/.DocumentRevisions-V100

— that is the path most commonly associated with versions, but not the only path.

Transparent App Lifecycle (TAL)

Rarely, you may encounter the expressions Transparent App Lifecyle, or TAL. Publicly available information suggests that:

• TAL includes auto save, versions and resume
• talagent is a helper agent — you'll see talagent in Activity Monitor.

File systems support for permanent version storage

The recent review by Ars Technica was probably limited to computers where only JHFS+ (Journaled HFS+) volumes were present.

Not all file systems support permanent version storage.

The following screenshot (taken from a work in progress) shows the type of dialogue that 10.7 may present when working with an application that supports the Transparent App Lifecycle with a file system without support for permanent version storage:

— observed whilst working with photographs on a camera where the partition type is DOS_FAT_16

Utilities such as Instruments (installed with freely available Xcode) or fseventer can reveal the paths that 10.7 uses in an environment such as the one pictured. In 10.7 (Build 11A511): subdirectories of ~/Library are used, with access not limited to the root user.

If data to support the TAL is inadvertently interfered with, we can not predict the consequences. Let's assume that bad things may happen. For this reason and others:

I strongly discourage people from making permanently visible the Library in the home directory

— if you wish to argue with that, please aim for a topic where ~/Library is a subject; thank you.

References

What's New in OS X Lion - Apple Developer — Auto Save and Versions — Resume)

Technical Note TN1150: HFS Plus Volume Format

• previously at http://developer.apple.com/library/mac/technotes/tn/tn1150.html
• not in the Internt Archive Wayback Machine
• TN1150 currently not found in Apple Developer areas

How do I get autosave to work in Lion 10.7?

… permanent version storage …

The document is on a volume that does not support permanent version storage.

Looking ahead

Expect Apple to publish additional information, including revised and additional manual pages, in due course.

Keyword: patience 🙂

For those of you with concerns about free space on disk: I believe that deltas are used.

A question in the Super User area uses the expression deltas. The best answer to that question directs to the same Ars Technica page as was offered by Colin Robinson. The Ars Technica article uses the expression chunks (not deltas).

Whatever the expression: it seems that Apple takes a very intelligent approach to not wasting space.