C-Command Software Forum

Sparse bundle disk image and use of Dropbox

I have been using an encrypted sparse bundle disk image of my EF library on Dropbox (1.0.28) on two different computers (both are OS 10.6.7) for a while now and it seems like every few months the EF library gets corrupted. I end up setting up a new library and dragging in the library records to recover my library. I know that you have to be careful when using an EF library with Dropbox but I am wondering what my most likely mistake has been.

Here is my usual procedure:

  1. Use the EF library at work on my office computer. At the end of the day, I always chose the Close & Lock command and then I close the EF program. I am positive that I always do this. I leave the computer on all the time.

  2. At home, my laptop is typically on all the time too but is in sleep mode with the cover closed. I open the laptop and awaken it. I think that I am pretty careful to allow Dropbox files to sync before opening the EF library, but I am wondering if maybe once in a while I forget to do this. I have a alias setup in the dock to open the EF library in Dropbox by clicking on it - so maybe that makes it more likely that I might not check to see if the files are done doing the sync.

  3. When the library become corrupted, it very quickly becomes unusable. Often it will not open up at all. Restoring with Time machine seems to fix it on the computer I am working on, but it runs very slowly and is probably corrupt in some way. It usually still has problems in the other computer too. I have other forms of backup in addition to Time Machine that I can use too.

Does it seem likely that my mistake is as described in #2 above - opening the library before syncing has finished? Is that always fatal?

What is the best way to recover from the case of the corrupted library - is it best to start with a new library as I have been doing?

Would there be an advantage to using the sparse disk image format instead of the sparse bundle disk image or not to use a disk image at all when using Dropbox? I thought that the sparse bundle disk image was the preferred way to go when using Dropbox but I am not sure if that applies to this particular issue of corruption.

Thanks for any suggestions.

What are the specific symptoms, aside from sometimes not being able to open the library? Does EagleFiler report that files are missing?

Have you verified that after choosing “Close & Lock” the white volume icon for the encrypted disk image has been ejected? That is, it should no longer appear in the Finder sidebar or on the desktop.

Also, before you open the library on another Mac, Dropbox on the office computer has to be finished syncing. You can verify this by looking at the Dropbox icon in the menu bar.

Just to be clear, the disk image itself should only be mounted on one Mac at a time. So it should be ejected on the home Mac while you’re at the office, then you come home and wait Dropbox to finish syncing before you mount it, and then open the library in EagleFiler.

That would be my guess.

It’s not necessarily fatal, but it’s almost certain to cause some problem. It’s especially bad to do this if you have an encrypted library.

Yes, it’s best to make a new library and follow this procedure to transfer your files.

The sparse bundle disk image format is more robust and faster than the sparse disk image format. It was initially necessary to use an encrypted library with Dropbox if you wanted to preserve your Mac metadata. However, Dropbox 0.8 and later have better support for metadata, so you can now store regular, unencrypted libraries on Dropbox. This is what I would recommend doing if you don’t need encryption. It’s more efficient, simpler (no mounting/ejecting), and less likely to cause serious problems if you forget to close the library. Also, when using an unencrypted library, multiple Macs can add and edit files simultaneously via the Finder. (As always, it should only be open in one copy of EagleFiler at a time.)

Thanks, that helps a lot. I’ll go back to using a regular unencrypted library. I don’t need the password protection. For some reason, I thought it would be more stable using the disk image strategy but it is good to know that the regular library will work ok.

To answer your questions:
Yes, there were usually a few files reported missing.
I normally checked to make sure the disk image was ejected when done using the library on either computer.
I think I would have been better off not using the alias on the home computer. If I had to click directly on the library file, I would have been more likely to check to make sure it was finished syncing.

Thanks again for your help