How do I backup my iPhoto library to Dropbox or to an external disk? I use iPhoto 11, and I'd like to backup the library, along with all the photos.

I'd ideally like a continuous backup, by putting the iPhoto Library.photolibrary file / package in Dropbox. But I'm concerned that Dropbox may not preserve everything HFS+ provides, such as:


Symlinks, hard links and aliases.
Resource forks and extended attributes.
File modification times. Imagine if iPhoto expects the library to have two files with one of them always having a modification time always older than the other's. When the files are synced to the cloud, and synced back to another device, does Dropbox guarantee to preserve the relative order of the modification times? If not, if I lose my Mac and buy a new one, the iPhoto library may be corrupt and unreadable (or things may appear to work but go wrong later).
Dropbox may have path length limits or may disallow certain characters in file names, etc.


I could not find any definitive documentation from either Dropbox or Apple about this.

Assuming that my reasoning above is correct -- that it's not safe to put my iPhoto Library in Dropbox -- that means that I can't have continuous backup.

In that case, I must do periodic backups, and hope nothing goes wrong in the meanwhile. Is it safe to backup the iPhoto library to a FAT32 filesystem?

I found http://support.apple.com/kb/TS5168 but it says only that I shouldn't run iPhoto with the library stored on a FAT32 disk, not that I shouldn't back it up to a FAT32 disk.

I also found http://support.apple.com/kb/ph2504 , which encourages us to back up to an external disk, but doesn't say if FAT32 is okay.
Let me take a stab at actually answering the question.

First of all, do NOT use a FAT32 drive to back up your iPhoto library. The library frequently contains aliases/symlinks, and FAT doesn't support those, so they would either result in duplicate photos (in the best case) or break a bunch of your photos.

I don't think Dropbox has any limitation that would prevent it from backing up any/all normal files you'd store on Mac, which would include filename restrictions. Those would be a dealbreaker for any syncing cloud storage. So I think you can be confident there.

Dropbox seems to handle symlinks by turning them into duplicates. Other than that, people have been moving their libraries over to the Dropbox folder successfully. Here's a post to that effect – and in the comments are some common problems and solutions to this technique.

I've also (through a post on Apple's forums) found an app called Insync which utilises your Google Drive account. They claim to support symlinks … in fact a large part of the draw is that you can create symlinks to anywhere on your computer and direct them to the Insync folder (which then goes to Google Drive). In other words, you should be able to create a link to your iPhoto library and it will make a synced backup, rather than having to actually move the library to a synced folder.