Was/is there another device connected to the account?

No, only my computer.

Note that this can happen if the computer name is the same. Then the Sync server thinks that the same device is connected and will upload the current data to the server and overwrite data that was previously stored. In such a case you would have to change the computer name before connecting to Sync to make the server believe that it's another device.

But I already replaced my sync data with fresh firefox data (I wanted to do exactly opposite thing). Besides, I was doing so on my computer after C: disc format, it has new name, should be considered to be new machine from perspective of sync service.

Hi Lunarinstincts, I am sorry however without a back up there are no work arounds that I can suggest to recover this data. Due to the merging model of Firefox Sync it sounds like the storage was overwritten with the same computer name.

For further questions please see the Firefox Accounts Terms of Service

So in other words, my bookmarks on the sync server were overwritten and there is nothing I can do about it?

...I guess, that I will never use sync option again. Just in case.

cor-el said

Note that this can happen if the computer name is the same. Then the Sync server thinks that the same device is connected and will upload the current data to the server and overwrite data that was previously stored. In such a case you would have to change the computer name before connecting to Sync to make the server believe that it's another device.

I'm afraid this is totally incorrect.

Sync will always merge what's on the local device with what's on the server.

My guesses as to what happened here:

1. You used to be using the old Firefox Sync, and now you're using Firefox Accounts. If you got an email saying that you needed to verify your email address, this is probably what happened.
2. You forgot your password, and had to reset it when you logged in after your reinstall. Sync uses end-to-end encryption; if you change your password, you can't recover your data.
3. Your bookmarks are still on the server, and there's some other reason why they're not syncing locally (e.g., one of them is malformed).
4. Your bookmarks did sync, but something went wrong. Look in Unsorted Bookmarks. Is anything else from your old profile syncing? (e.g., history)
5. You were never syncing your bookmarks. See if the checkbox is checked in Preferences.

rnewman@mozilla.com said

cor-el said

Note that this can happen if the computer name is the same. Then the Sync server thinks that the same device is connected and will upload the current data to the server and overwrite data that was previously stored. In such a case you would have to change the computer name before connecting to Sync to make the server believe that it's another device.

I'm afraid this is totally incorrect.

Sync will always merge what's on the local device with what's on the server.

My guesses as to what happened here:

1. You used to be using the old Firefox Sync, and now you're using Firefox Accounts. If you got an email saying that you needed to verify your email address, this is probably what happened.
2. You forgot your password, and had to reset it when you logged in after your reinstall. Sync uses end-to-end encryption; if you change your password, you can't recover your data.
3. Your bookmarks are still on the server, and there's some other reason why they're not syncing locally (e.g., one of them is malformed).
4. Your bookmarks did sync, but something went wrong. Look in Unsorted Bookmarks. Is anything else from your old profile syncing? (e.g., history)
5. You were never syncing your bookmarks. See if the checkbox is checked in Preferences.

Thx for reply. Like I said, instead of loading bookmarks (yes, bookmarks were selected for syncing) i uploaded default, fresh-firefox bookmarks, thus my old ones were overwritten. I checked this out, because I reinstalled FF, deleted default bookmarks to have non at all, and after syncing bookmarks I retreieved default ones- as a filan proof that my old bookmarks are not on the server anymore.

It's a shame, that sync server doesn't have "slots" or at least backup system, that would be so nice and fool-proof. And I lost them like a complete idiot.

Lunarinstincts said

Thx for reply. Like I said, instead of loading bookmarks (yes, bookmarks were selected for syncing) i uploaded default, fresh-firefox bookmarks, thus my old ones were overwritten.

With respect, this is not how Sync works, at all.

Before any bookmark records are uploaded, the records on the server are downloaded and merged.

There's no concept of "replacing", or of sets of bookmarks, or overwriting. Connecting a new device will never remove anything from the server.

I'm sorry that your bookmarks have gone missing, but it sounds like whatever went wrong happened long before you connected your new profile.

I hope you can find a backup of your profile so that you can restore your data.

Anyway, when I reinstalled FF first time, I logged into my sync account and nothing happened.