Question

When I install Firefox and move it to the SD card, the app only uses a few Megabytes worth of space (See the screenshot above to show the space, according to Android). Firefox functions fine. But eventually Firefox grows to be much larger.

The installer is approximately 20 megs. There is no way for Firefox to use less than that.

Stefan have you moved yor FF to SD card? Application takes very little of space but data takes a lot. I`ve got similar problem - 32 MB of data - my Sync account takes 6,6....

Yes, I have moved Firefox to the SD card. According to Android, Firefox only uses 1.85MB on the main system storage.

      Application: 1.85MB

I'll update my question to state that Firefox has been moved to the SD card.

> The installer is approximately 20 megs

But note that according to Android, Firefox only uses 1.85MB on my system:

      Application: 1.85MB
      Data: 27.76MB

I should clarify that I moved Firefox to the SD card. The bulk of the 20MB application lives on the SD card. But Data grows from a few MB to 30+ MB within a few days.

That's what i thought Stefan. I cannot move my apps to SD, so now i`ve got firefox with ober 80 MBs on my phones memory!

So i`ve check it and i found something interesting: Folder /data/data/org.mozilla.firefox/files/mozilla/wl5xm96h.defult/Cache takes 43.31 MB! So why cache folder takes 43MB??

Olaf, I have come to the same conclusions. The Cache is at fault here.

The four largest directories under /data/data/org.mozilla.firefox are:

   1MB    	./files/mozilla/$uniqueid.default/indexedDB/chrome
   1MB    	./files/mozilla/$uniqueid.default/indexedDB
   3MB    	./files/mozilla/$uniqueid.default/safebrowsing
   5-30MB	./files/mozilla/$uniqueid.default/Cache

(Note that I obfuscated my unique identifier)

I've been reading up on the Cache settings (browse to about:config and search for 'cache'), but some of those settings are not well documented.

Also note that Android's "Clear Cache" does not work with the Firefox cache.

I have a more detailed analysis of the problem. I believe this is a bug in Firefox, and I will file a bug report later. Look below for my temporary workaround.

Firefox has a feature known as a "Smart cache". I cannot find much information about this cache, but the name suggests that the size of the "Smart cache" is determined automatically.

To see the value of your cache, browse to "about:cache" and note the values. For me, "Maximum storage size" is currently 256000 KiB (Yes -- 200MiB). This value is equal to the value of browser.cache.disk.capacity, which was modified by Firefox from it's default value of 20480.

   Disk cache device
   Number of entries:     321
   Maximum storage size:     256000 KiB
   Storage in use:     2561 KiB
   Cache Directory:     /data/data/org.mozilla.firefox/files/mozilla/removed.default/Cache
   List Cache Entries

My workaround

Here is my temporary workaround to adjust the size of the cache. I am experimenting with these settings, but I feel these settings are okay for my low-end Android phone.

Go to 'about:cache', search for 'cache' and then change the following values

1. Disable the smart cache:

   browser.cache.disk.smart_size.enabled=false

1. Set the disk cache to a small value. This might be too small in the eyes of some developers, and I am open to better values. The default is 20480 (20M) which is way too large for my phone.

   browser.cache.disk.capacity=2048

1. Cache compression is disabled by default. Turn it on, and set compression to a reasonable level (1-9, where 1 is low CPU usage but low compression, and 9 is high CPU usage and high compression).

   browser.cache.compression_level=6

Verify

1. Browse to 'about:cache' and note that the new value for ' Maximum storage size' is 2048.

Another culprit is webappsstore.sqlite*, which on my phone uses 10MB worth of space. See below (I included the 5 largest subdirectories for comparison).

   # pwd
   /data/data/org.mozilla.firefox/files/mozilla/foo.default
   # du -ks * | sort -n
   ...
   1049    startupCache
   3549    safebrowsing
   4096    webappsstore.sqlite
   6072    adblockplus
   6149    webappsstore.sqlite-wal 
   #
   # du -ks /data/data/org.mozilla.firefox/files/mozilla*
   34777   /data/data/org.mozilla.firefox/files/mozilla

This is marked as a bug, but I don't know if there is any workaround or solution for this.

https://bugzilla.mozilla.org/show_bug.cgi?id=857888

And, if I move Firefox from the SD Card back to the Phone memory, Firefox 20 uses 62MB of space:

Here are two screenshots:

https://www.dropbox.com/s/qzecjr93z67zpw1/shot_000003.png https://www.dropbox.com/s/d6731nvgh3wueyj/shot_000004.png

I was regularly Firefox's Clear Data and Cache from the Application manager. Since Link2SD won't move the data files to sdcard, I had to do it manually. but first the device must be rooted and busybox is installed on the device.

now I moved the files and cache directory from /data/data/org.mozilla.firefox to my sdcard's second partition. The /data/data/org.mozilla.firefox directory now has less than 2 MB, and it is stable in that size

This is a great tip, and I've been looking for something like that for some time.

I would only add that you could also specify where to store the cache files using the browser.cache.disk.parent_directory property, for example, to use external storage.

Please, note that this property is not there for a good reason (you'll have to add it manually). Putting your Cache data in a removable device is not a good idea, as it can easily been extracted, and copied elsewhere, compromising your privacy and security. But if you keep your smartphone with you all the time, then you can assume the risk of trading for a small amount of valuable internal storage space.

Thanks for pointing out the option for `browser.cache.disk.parent_directory`. I understand the privacy implications of storing the cache outside the profile directory, but I don't have much choice. Firefox as an App grew quite a bit with the latest release (8MB worth of fonts) and my phone was so full that the system wasn't applying security updates to other Apps. I either need to get this disk space problem resolved or I will have to stop using Firefox.

I did this to free up space:

1. Created a new directory on my sdcard (`/mnt/sdcard/something/`)
2. Under `about:config` set browser.cache.disk.parent_directory to match the new directory created above.
3. Restart Firefox (I had to kill the Firefox app)
4. Went to a few cache-heavy websites like Facebook and Pinterest
5. Verified that the cache was working under `about:cache`
6. Deleted the old cache files under my foo.profile/Cache directory
7. Went to `about:config` and reverted a few of my manual settings which I set months ago to conserve disk space.

Now Firefox uses 10MB less space on my system memory then it did before. I can also make the cache larger (much larger) which will speed up the viewing of webpages.

I could not create a symlink from my old Cache directory to the new Cache directory.

More info about ` browser.cache.disk.parent_directory` can be found at http://kb.mozillazine.org/Browser.cache.disk.parent_directory

I requested that the Developers allow us to move the 8MB worth of fonts from internal storage to the SD Card:

https://bugzilla.mozilla.org/show_bug.cgi?id=878674