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Moving Firefox across drives

  • 5 replies
  • 1 has this problem
  • Last reply by cor-el

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Sorry if this is a stupid question - I just can't find anything online that works. I'm trying to move the entirety of Firefox from my C:\ drive to my D:\ drive in order to reduce writes to my SSD. I'm trying to use mklink with this command to move my profiles from appdata:

mklink /J "C:\Users\[name]\AppData\Roaming\Mozilla\Firefox\Profiles" "D:\Programs\AppData\Roaming\Mozilla\Firefox\Profiles"

However, when I try and execute it I get the result "Cannot create a file when that file already exists." Does anyone know how to fix this?

All Replies (5)

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If anyone has a better way of doing this other than using mklink, i'd appreciate that too :)

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Are you talking about moving just the profile, just the program, or both?

What's your computer system and Firefox version?

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FredMcD said

Are you talking about moving just the profile, just the program, or both? What's your computer system and Firefox version?

Hi Fred, thanks for the reply I only want to move the profiles and cache data from my app data folders. I've already moved the program across through reinstalling it :)

I'm using Windows 10 x64 and my Firefox version is 79.0 (64-bit)

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On the other hard drive, create a folder where you want to store the profile.

Type about:profiles<enter> in the address bar. Select Create New Profile.

Select the folder you just created including the drive information. ex: "D:\Mozilla\Firefox\Profiles\<==profile name==>"

After, make sure the new profile works properly.

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Hi best is to create a new profile on that D-drive and copy specific files from the old profile to the new profile. You can create a new folder on beforehand on the D-drive to be used for this profile and use "Choose Folder" in the dialog to create a new profile and point to this folder.

You can copy specific files with Firefox closed to the current profile folder to recover/transfer specific personal data.

  • bookmarks and history: places.sqlite
  • favicons: favicons.sqlite
  • bookmark backups: compressed .jsonlz4 JSON backups in the bookmarkbackups folder
  • cookies.sqlite for the Cookies
  • formhistory.sqlite for saved autocomplete Form Data
  • logins.json (passwords) and key4.db (58+) or key3.db (57 and older) (decryption key) for Passwords saved in the Password Manager
    if you only have key3.db then make sure to remove an existing key4.db
  • cert9.db (58+) or cert8.db (57 and older) for (intermediate) certificates stored in the Certificate Manager
    if you only have cert8.db then make sure to remove an existing cert9.db
  • persdict.dat for words you added to the spelling checker dictionary
  • permissions.sqlite for Permissions and possibly content-prefs.sqlite for other website specific data (Site Preferences)
  • sessionstore.jsonlz4 for open tabs and pinned tabs (see also the sessionstore-backups folder)

You can use the button on the "Help -> Troubleshooting Information" (about:support) page to go to the current Firefox profile folder or use the about:profiles page.