Assuming that there is memory to spare, placing Firefox's cache or complete profile to RAM offers significant advantages. Even though opting for the partial route is an improvement by itself, the latter can make Firefox even more responsive compared to its stock configuration. Benefits include, among others:

reduced drive read/writes;

heightened responsive feel;

many operations within Firefox, such as quick search and history queries, are nearly instantaneous.

To do so we can make use of a tmpfs.

Because data placed therein cannot survive a shutdown, a script responsible for syncing back to drive prior to system shutdown is necessary if persistence is desired (which is likely in the case of profile relocation). On the other hand, only relocating the cache is a quick, less inclusive solution that will slightly speed up user experience while emptying Firefox cache on every reboot.

Relocate cache to RAM only

See Firefox/Tweaks#Turn off the disk cache.

Relocate the browser profile to tmpfs so as to globally improve browser's responsiveness. Another benefit is a reduction in drive I/O operations, of which SSDs benefit the most.

Use an active management script for maximal reliability and ease of use. Several are available from the AUR.

- refer to the Profile-sync-daemon wiki article for additional info on it;

AUR - sufficient for a user with a single profile; uses a script and systemd service similar to those below.

Place profile in RAM manually

Before you start

Before potentially compromising Firefox's profile, be sure to make a backup for quick restoration. Replace xyz.default as appropriate and use tar to make a backup:

$ tar zcvfp ~/firefox_profile_backup.tar.gz ~/.mozilla/firefox/xyz.default

The script

Adapted from verot.net's Speed up Firefox with tmpfs

The script will first move Firefox's profile to a new static location, make a sub-directory in /dev/shm , softlink to it and later populate it with the contents of the profile. As before, replace the bold sections to suit. The only value that absolutely needs to be altered is, again, xyz.default .

Be sure that rsync is installed and save the script to ~/.local/bin/firefox-sync , for example:

firefox-sync

#!/bin/sh static=static-$1 link=$1 volatile=/dev/shm/firefox-$1-$USER IFS= set -efu cd ~/.mozilla/firefox if [ ! -r $volatile ]; then mkdir -m0700 $volatile fi if [ "$(readlink $link)" != "$volatile" ]; then mv $link $static ln -s $volatile $link fi if [ -e $link/.unpacked ]; then rsync -av --delete --exclude .unpacked ./$link/ ./$static/ else rsync -av ./$static/ ./$link/ touch $link/.unpacked fi

Close Firefox, make the script executable and test it:

$ killall firefox firefox-bin $ chmod +x ~/.local/bin/firefox-sync $ ls ~/.mozilla/firefox/ $ ~/.local/bin/firefox-sync <firefox-profile>

Run Firefox again to gauge the results. The second time the script runs, it will then preserve the RAM profile by copying it back to disk.

Automation

Seeing that forgetting to sync the profile can lead to disastrous results, automating the process seems like a logical course of action.

systemd

Save the following script as ~/.config/systemd/user/firefox-profile@.service

then use

systemctl --user daemon-reload systemctl --user enable firefox-profile@<profile>.service systemctl --user start firefox-profile@<profile>.service

[Unit] Description=Firefox profile memory cache [Install] WantedBy=default.target [Service] Type=oneshot RemainAfterExit=yes ExecStart=/home/matthew/.local/bin/firefox-sync %i ExecStop=/home/matthew/.local/bin/firefox-sync %i

cron job

Manipulate the user's cron table using crontab :

$ crontab -e

Add a line to start the script every 30 minutes,

*/30 * * * * ~/.local/bin/firefox-sync

or add the following to do so every 2 hours:

0 */2 * * * ~/.local/bin/firefox-sync

Sync at login/logout

Assuming bash is being used, add the script to the login/logout files:

$ echo '~/.local/bin/firefox-sync' | tee -a ~/.bash_logout ~/.bash_login >/dev/null

Note: You may wish to use ~/.bash_profile instead of ~/.bash_login as bash will only read the first of these if both exist and are readable.