1554460 - Respect Windows Storage Conventions by storing more files under %LocalAppData%

Status: RESOLVED DUPLICATE of bug 1395705

(Toolkit :: Storage, defect)

Description

[Micah Zoltu]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0

Steps to reproduce:

Installed and used Firefox.

Actual results:

It wrote 700MB of data to %APPDATA%/Mozilla.

Expected results:

It should have written the vast majority of this data to %LOCALAPPDATA%.

On Windows, %APPDATA% is roaming storage, which means it is synced over a network or over the internet. Files in %APPDATA% should be limited to user configuration files and other small content that is user-specific and should roam. %LOCALAPPDATA% does not automatically roam or sync over the internet, so it is a much more appropriate place to store large user-specific data such as caches or local storage.

A default Firefox install currently will wreak havok on backup systems that sync over the internet or over a network on login/logout. Please respect Windows storage path conventions and move large user-specific storage to %LOCALAPPDATA%.

Comment 1

[Gingerbread Man]

(In reply to Micah Zoltu from comment #0)

It wrote 700MB of data to %APPDATA%/Mozilla.

What files specifically?

%LOCALAPPDATA% [...] is a much more appropriate place to store large user-specific data such as caches or local storage.

%LocalAppData%\… is the default location for both the disk cache and app cache, unless manually configured otherwise. You can check the paths by entering about:cache into the location bar.

Comment 2

[Micah Zoltu]

storage makes up over half of it, and several sqlite files make up a big chunk of the remaining. You can see a size distribution at https://snag.gy/7Ri52b.jpg

Digging a bit in to the storage folder, I see default and temporary. Right off the bat temporary should not be roaming. Glancing through default, it appears to be a folder for each site, with a large cache folder inside each. cache files should all be in %LOCALAPPDATA%, as they don't need to roam across a network. I also see extensions and backups in there, which are similarly not user-config, and thus not appropriate for %APPDATA%, as well as Crash Reports, which are definitely not something that should roam/be backed up.

After spending a few minutes digging through the profile folder, everything I see that is of significant size is not appropriate for roaming storage. I suspect somewhere in there are config files that are appropriate for roaming (like bookmarks, preferences, etc.) but those files are likely measured in kilobytes.

Looking at about:cache, it appears Firefox is correctly configured to use %LOCALAPPDATA%. It appears the problem is that Firefox is writing a lot of files that should be written to cache locations into non-cache locations (like the user profile folder).

Comment 3

[Gingerbread Man]

Attachment: Repoter's screenshot at comment 2.jpg

:Gijs, you were involved with bug 1339696. I'd appreciate it if you could either triage or resolve this.