Sync is meant to share data between several systems. not as a backup.

These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.

OPIE {web link} Import/Export extension preferences

Thanks, Fred. That sounds useful, but I'm still left with the original question. Does syncing only go in one direction or does it create a superset of merged data when I sync both my laptop and my desktop? What if I want these to be different for work/personal machines? And other questions raised in my original comment.

This link may answer some of your questions; https://support.mozilla.org/en-US/search?esab=a&w=1&q=sync

Without advice to the contrary, I just spent *two hours* organizing 300 bookmarked webpages into folders and checking that they were still accurate and current. I wanted my laptop to be have the same degree of organization, so deleted and did a clean install of Firefox on it. Ready to be synced. So I'm at my desktop now and I soon as I signed in to sync, I LOST ALL OF THE FREAKING BOOKMARK FOLDERS. WTF? Can someone please, once again, address my initial question. Also, Is there some way to get my work back? Does a system restore also restore the AppData Roaming folder for Mozilla to restore my bookmark preferences? OMG the pain!

In case Firefox had already created a compressed .jsonlz4 then you can restore the bookmarks from such a backup.

The name of a JSON bookmarks backup file includes a total item count (folders and separators included) and an hash value to prevent saving the same backup more than once.

• bookmarks-YYYY-MM-DD_<item count>_<hash>.jsonlz4.

• https://support.mozilla.org/kb/restore-bookmarks-from-backup-or-move-them

Thanks, Corel. Restored now, but how do I get the organized bookmarks over to my laptop unless it's through syncing? Syncing just screwed everything up.

You can use a USB stick (jump drive) and copy the backup to that drive and take it to the other computer.

You can use an HTML backup if you want to merge bookmarks because restoring a JSON backup will always replace all bookmarks.

That's how I've always done it in the past, but I thought the "beauty" of Firefox Sync was that I could have the same settings, bookmarks and history on all of my devices. That's why I asked if it can be uni-directional (computer to Firefox server only) or if the data is mashed into supersets with sync's from multiple devices. Supersets get very messy, as this last sync ended up scrambling all the work I'd just done.

PS. I understand that if I had been logged in to Firefox Sync at the time I organized the bookmarks, the folders would have been synced in "the cloud". Gives me an idea...

To protect your profile from being damaged or lost, use these;

These can't get your data back, but will help in the future.

These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backups of files that you choose.

OPIE {web link} Import/Export extension preferences

KenovaOne said

... That's why I asked if it can be uni-directional (computer to Firefox server only) or if the data is mashed into supersets with sync's from multiple devices. Supersets get very messy, as this last sync ended up scrambling all the work I'd just done.

There is no "control" over Sync as far as the "direction" that Sync data flows. All data gets merged on the Sync server. And then merged with the other devices as each of those devices are connected to Sync.

The "control" that the user does have is the types of data that is included in the Sync process. Tabs, Bookmarks, Passwords, History, Add-ons and Preferences.

An earlier version, Sync 1.1 did have a bit more control, as far as "direction", but the current Sync 1.5 version did away with that.

Thanks. That's the first time I've heard it explicitly stated like that. I backed up my best Firefix setup with the extension recommended by Fred above, then logged in to sync on the clean install on my laptop while restoring from the copied backup from the tower. Then synced the final product. Now my desktop, laptop and the Firefox server all have my best tweaked version. Thank you all for your help!

If anyone can add info on how it merges data, why it keeps some folders, or chooses old versions of passwords over new ones, I'm curious about the code/algorithm. Thanks.