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Firefox profile manager problems for backing and restoring - a request

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  • Last reply by neyuru

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I expect backing my profile following the recommended steps (https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles):

1) Back up my profile. 2) Reinstall Firefox (or Windows and then firefox) 3) Choose the backup folder, TO: 4) Continue use of firefox as if reinstall was never performed.

But the Firefox process is making this difficult for me. There are two folders that firefox uses: the "profile" and the "cache" folder. Now, it is only possible to back up the "profile" folder. When you reach point (3) above, the built in profile manager (firefox.exe -P) only lets you choose the desired "profile" folder location and not the "cache". When you finish the setup in the profile manager, as Firefox does not have the "cache" folder, it creates ITS CONTENTS inside the backed "profile" folder. You have now then, unwillingly, merged the 2 folders in one.

Profile Manager must have the option to choose BOTH origin and destination folders for BOTH "profile" and "cache" folders. So that backing up Firefox experience is more seamless.

I expect backing my profile following the recommended steps (https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles): 1) Back up my profile. 2) Reinstall Firefox (or Windows and then firefox) 3) Choose the backup folder, TO: 4) Continue use of firefox as if reinstall was never performed. But the Firefox process is making this difficult for me. There are two folders that firefox uses: the "profile" and the "cache" folder. Now, it is only possible to back up the "profile" folder. When you reach point (3) above, the built in profile manager (firefox.exe -P) only lets you choose the desired "profile" folder location and not the "cache". When you finish the setup in the profile manager, as Firefox does not have the "cache" folder, it creates ITS CONTENTS inside the backed "profile" folder. You have now then, unwillingly, merged the 2 folders in one. Profile Manager must have the option to choose BOTH origin and destination folders for BOTH "profile" and "cache" folders. So that backing up Firefox experience is more seamless.

All Replies (6)

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You're right that Firefox does not have a convenient method to recognize and run a copy/pasted old profile folder. Various tricks mentioned in the article are needed.

But you don't need to worry about the cache folder; Firefox will just re-download web pages and associated files as needed. The data in the profile folder is the valuable stuff.

neyuru said

When you finish the setup in the profile manager, as Firefox does not have the "cache" folder, it creates ITS CONTENTS inside the backed "profile" folder. You have now then, unwillingly, merged the 2 folders in one.

I don't understand what happened there. The general process is:

(1) Get your data from here:

C:\Users\your-username\AppData\Roaming\Mozilla\Firefox\Profiles\your.profile

(2) On the new system, create a new profile, start Firefox in that profile, open the profile folder, and exit Firefox

(3) Clear out the contents of the new profile folder and put the contents of the old profile folder into it (keeping the new profile folder name)

(4) Start Firefox and it looks in the new profile folder and finds the contents of the old profile folder; transplant successful

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Sorry for the confusion, I performed Thunderbird's recommended profile restore ( https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer ) which prompts you too choose the backed up folder when using the profile manager (thunderbird.exe -profilemanager).

In this way, backing and restoring Thunderbird actually works the way I am expecting as there is only one folder to back up in contrast to Firefox. If you do this with Firefox:

1) Back your profile (the real "profile" folder) 2) uninstall, reinstall Firefox, 3) start the profile manager, and then 4) create a profile choosing the backed folder, and then 3) accept...

Then Firefox copies all the folders and files that are intended in the "cache" folder in the location of the backed up folder, effectively merging the once separated folders into one. I am not manually copying the contents of the backed folder into a newly generated random profile... which I guess it will eliminate this problem of "merging" the aforementioned folders.

I know the cache folder is not that very important but I was applying this alternate way of backing and restoring and found out that, not only Firefox is OK with it, but also merges the folders together. Not a big deal after all because it doesn't crash anything, but an unsuspecting user who does the same thing as I did, will end up with a folder worth several GigaBytes of valuable space (because the cache folder will keep growing resintall after reinstall and after multiple restores of firefox)

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Not a good idea to compare how Firefox and Thunderbird work in that regard. Different developers who aren't part of Mozilla, for the most part; a separate organization that receives support from Mozilla, mostly with hosting the Thunderbird project now.


I think your issue is with creating a new Profile and copying your Profile data into that new Profile which has a different Profile name; then the "secondary" Profile folder in "Local" appends the "old" data in that new secondary Profile folder. If I read your explanation correctly.


Forget about Mozilla fixing something like that anytime soon, if ever; the current Profile Manager will probably be replaced soon, so more "patching" of it probably isn't "in the cards".


I think the way around that is to use the original profiles.ini file that is one folder above the "primary" Profile folder.

IOW, save this folder - which contains the profiles.ini file AND the "primary" Profile folder below that folder level in Windows.

C:\Users\user-name\AppData\Roaming\Mozilla\Firefox\Profiles\

And also copy the "secondary" Profile folder location here:

C:\Users\user-name\AppData\Local\Mozilla\Firefox\Profiles\profile-name

Then paste & replace each of those folders into the 'receiving' Windows OS.

The idea is to not fiddle with the Profile Manager & a new Profile and to NOT change the Profile name; but rather move the profiles.ini file along with the entire primary Profile folder over to the "new device" intact. And to move the "secondary" Profile folder over with its Profile name. That way you avoid "merging" the contents of the "secondary" Profile folder cache contents, which doesn't work too well.

Worked for me a few years ago when I was setting up a new PC that I built. Firefox was the same on the new PC as when I copied the two Profile folders (primary and secondary) from the older one, and went from WinXP to Win7 on the new one.

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The cache folder will only be in the main profile folder if you do not create the profile in the default, but use Choose Folder to create/register a folder elsewhere (AppData\Roaming).

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the-edmeister said

Not a good idea to compare how Firefox and Thunderbird work in that regard. Different developers who aren't part of Mozilla, for the most part; a separate organization that receives support from Mozilla, mostly with hosting the Thunderbird project now.

Maybe so, but what does a layman user see in https://support.mozilla.org/en-US/ ? The average user doesn't care if there are differences between these two projects, it only sees the umbrella company and assumes both to be treated in the same philosophy

the-edmeister said

I think your issue is with creating a new Profile and copying your Profile data into that new Profile which has a different Profile name; then the "secondary" Profile folder in "Local" appends the "old" data in that new secondary Profile folder. If I read your explanation correctly.

Yes, although name changing is not an issue, only the merger.

the-edmeister said

Forget about Mozilla fixing something like that anytime soon, if ever; the current Profile Manager will probably be replaced soon, so more "patching" of it probably isn't "in the cards".

Well, as a regular user I'm unpledged and neutral to the actual implementation route that could fix this so:

the-edmeister said

I think the way around that is to use the original profiles.ini file that is one folder above the "primary" Profile folder.

is a solution, then I don't see why it can't be implemented in code so that it is transparent to the user. Maybe with the default option to *not* save the cache files to reduce backup size. As I said before:

neyuru said

I know the cache folder is not that very important but I was applying this alternate way of backing and restoring and found out that, not only Firefox is OK with it, but also merges the folders together. Not a big deal after all because it doesn't crash anything, but an unsuspecting user who does the same thing as I did, will end up with a folder worth several GigaBytes of valuable space (because the cache folder will keep growing resintall after reinstall and after multiple restores of firefox)

The possibility to create a big backup file to an unsuspecting user is possible.

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cor-el said

The cache folder will only be in the main profile folder if you do not create the profile in the default, but use Choose Folder to create/register a folder elsewhere (AppData\Roaming).

Well yes, as the idea of backing up is storing it elsewhere, no?