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Revision as of 02:39, 28 November 2012 by Graysky (talk | contribs) (Using psd)
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Benefits of Psd

Running this daemon is beneficial for two reasons:

  1. Reduced wear to physical discs
  2. Speed

Since the profile(s), browser cache*, etc. are relocated into tmpfs (RAM disk), the corresponding onslaught of I/O associated with using the browser is also redirected from the physical disc to RAM, thus reducing wear to the physical disc and also greatly improving browser speed and responsiveness. For example, the access time of RAM is on the order of nanoseconds while the access time of physical discs is on the order of milliseconds. This is a difference of six orders of magnitude or 1,000,000 times faster.

Note: Chromium actually keeps its cache directory separately from its browser profile directory. It is not within the scope of profile-sync-daemon to modify this behavior; users are encouraged to refer to the Chromium_Tips_and_Tweaks#Cache_in_tmpfs section of the main Chromium_Tips_and_Tweaks article for several work-arounds.

Supported Browsers and Caveats

Currently, the following browsers are auto-detected and managed:

Setup and Installation

Profile-sync-daemonAUR is available for download from the AUR. Build it and install like any other package.

Edit /etc/psd.conf

Edit the included /etc/psd.conf defining which user(s) will have their profiles managed by psd.


# List users separated by spaces whose browser(s) profile(s) will get symlinked 
# and sync'ed to tmpfs.
# Do NOT list a user twice!
USERS="facade happy"
Note: At least one user must be defined.

Optionally uncomment the BROWSERS array and populate it with whichever browser(s) are to be sync'ed to tmpfs. If the BROWSERS array stays commented (default) then all supported browser profiles will be sync'ed if they exist.

Example: Let's say that both chromium and mirdori are installed but only chromium is to be sync'ed to tmpfs since the user keeps Midori as a backup browser and it is seldom used:

# List browsers separated by spaces to include in the sync. Useful if you do not
# wish to have all possible browser profiles sync'ed.
# Possible values:
#   chromium
#   firefox
#   google-chrome
#   heftig-aurora 
#   midori
#   opera
#   opera-next
#   qupzilla
# If the following is commented out (default), then all available/supported 
# browsers will be sync'ed

Optionally redefine the location of the tmpfs mount to use for syncs. Do this in the VOLATILE variable. Note that for Arch Linux, the default value of "/tmp" should work just fine.

Using psd

The initial synchronization will occur when the pseudo-daemon starts. Additionally, cron (if running) will call it to sync or update once per hour. Finally, psd will sync back a final time when it is called to stop.

The provided daemon file should be used to interact with psd (/usr/lib/systemd/system/psd.service):

# systemctl [option] psd.service

Available options:

start  Turn on daemon; make symlinks and actively manage targets in tmpfs.
stop  Turn off daemon; remove symlinks and rotate tmpfs data back to disc.
enable  Autostart daemon when system comes up.
disable  Remove daemon from the list of autostart daemons.

Enable psd to start/stop at boot/shutdown (highly recommended) using:

# systemctl enable psd.service

Sync at More Frequent Intervals (Optional)

Note: This step is NOT required. Psd will update once per hour on its own thanks to /etc/cron.hourly/psd-update -- psd does NOT remain running in memory!

Users wishing to have syncs occur more frequently can simply add a line to the root crontab to call the sync function of psd like so:

# crontab -e

Example syncing all profiles being managed once every ten minutes:

 */10 * * * *     /usr/bin/profile-sync-daemon sync &> /dev/null

Debug Mode

The debug option can be called to show users exactly what psd will do based on the /etc/psd.conf entered. Call it like so:

$ profile-sync-daemon debug

As stated above, if no specific browser or set of browsers are defined in the BROWSERS array, psd will sync ALL profiles that it finds for the given user.


Post in the discussion thread with comments or concerns.