1profile-sync-daemon(1) profile-sync-daemon(1)
2
6 profile-sync-daemon - Symlinks and syncs browser profiles to RAM
7 (tmpfs) thus reducing HDD/SSD calls and speeding up browsers.
8
10 Profile-sync-daemon (psd) is a tiny pseudo-daemon designed to manage
11 browser profile/profiles in tmpfs and to periodically sync back to the
12 physical disc (HDD/SSD). This is accomplished by an innovative use of
13 rsync to maintain synchronization between a tmpfs copy and media-bound
14 backup of the browser profile/profiles. Additionally, psd features sev‐
15 eral crash-recovery features.
16 Design goals of psd:
18 • Completely transparent user experience.
20 • Reduced wear to physical discs (particularly SSDs).
22 • Speed.
24 Since the profile/profiles, browser cache*, etc. are relocated into
26 tmpfs (RAM disk), the corresponding I/O associated with using the
27 browser is also redirected from the physical disc to the RAM, thus re‐
28 ducing wear to the physical disc and improving browser responsiveness.
29 *Note that some browsers such as Chrome/Chromium, Firefox (since v21),
31 Midori, and Rekonq actually keep their cache directories separate from
32 their browser profile directory. It is not within the scope of profile-
33 sync-daemon to modify this behavior; users wishing to relocate this di‐
34 rectory, may refer to the following url for several work-arounds:
35 https://wiki.archlinux.org/in‐
36 dex.php/Chromium_Tips_and_Tweaks#Cache_in_tmpfs
37
39 $XDG_CONFIG_HOME/psd/psd.conf (referred to hereafter as "the config
40 file") contains all user managed settings.
41 NOTE: edits made to the config file while psd is active will be applied
43 only after the service has been restarted.
44 • Optionally enable the use of overlayfs to improve sync speed
46 and to use a smaller memory footprint. Do this in the
47 USE_OVERLAYFS variable. The user will require no password
48 sudo rights to /usr/bin/psd-overlay-helper to use this option
49 and the kernel must support overlayfs version 22 or higher.
50 See the FAQ below for additional details.
51 • Optionally have psd resync to the filesystem prior to a sleep
53 call. This can help in the event that the system does not
54 properly wake up. Do this in the USE_SUSPSYNC variable.
55 • Optionally define which browsers are to be managed in the
57 BROWSERS array. If none are defined, the default is all de‐
58 tected browsers.
59 • Optionally disable the use of crash-recovery snapshots (not
61 recommended). Do this in the USE_BACKUPS variable.
62 • Optionally define the number of crash-recovery snapshots to
64 keep. Do this in the BACKUP_LIMIT variable.
65 NOTE: occasionally, updates/changes are made to the default config file
67 (/usr/share/psd/psd.conf) upstream. The user copy ($XDG_CON‐
68 FIG_HOME/psd/psd.conf) will need to be diffed against it.
69
71 PREVIEW MODE
72 The preview option can be called to show users exactly what psd will
73 do/is doing based on the entries in the config file. It will also pro‐
74 vide useful information such as profile size, paths, and if any recov‐
75 ery snapshots have been created.
76 $ psd p
78 Profile-sync-daemon v6.39
80 systemd service: active
82 resync-timer: active
83 sync on sleep: enabled
84 use overlayfs: enabled
85 Psd will manage the following per /home/facade/.config/psd/.psd.conf settings:
87 browser/psname: chromium/chromium
89 owner/group id: facade/100
90 sync target: /home/facade/.config/chromium
91 tmpfs dir: /run/user/1000/facade-chromium
92 profile size: 93M
93 overlayfs size: 39M
94 recovery dirs: 2 <- delete with the c option
95 dir path/size: /home/facade/.config/chromium-backup-crashrecovery-20200423_171359 (92M)
96 dir path/size: /home/facade/.config/chromium-backup-crashrecovery-20200424_112204 (93M)
97 browser/psname: firefox/firefox
99 owner/group id: facade/100
100 sync target: /home/facade/.mozilla/firefox/f8cv8bfu.default
101 tmpfs dir: /run/user/1000/facade-firefox-f8cv8bfu.default
102 profile size: 145M
104 overlayfs size: 13M
105 recovery dirs: none
106 START AND STOP PSD
109 Psd ships with a systemd user service to start or stop it (psd.ser‐
110 vice). Additionally, a provided resync-timer will run an hourly resync
111 from tmpfs back to the disk. The resync-timer is started automatically
112 with psd.service so there is no need to start the timer; only start
113 psd.service.
114 $ systemctl --user [option] psd.service
116 Available options: start stop enable disable
118 CLEAN MODE
120 The clean mode will delete ALL recovery snapshots that have accumu‐
121 lated. Only run it when sure these are no longer needed.
122 $ psd c
124 Profile-sync-daemon v6.39
126 Deleting 2 crashrecovery dirs for profile /home/facade/.config/chromium
128 /home/facade/.config/chromium-backup-crashrecovery-20200423_171359
129 /home/facade/.config/chromium-backup-crashrecovery-20200424_112204
130
133 • Chromium (stable, beta, and dev)
134 • Conkeror
136 • Epiphany
138 • Falkon
140 • Firefox (stable, beta, and aurora)
142 • Firefox-trunk (this is an Ubuntu-only browser: http://www.we‐
144 bupd8.org/2011/05/install-firefox-nightly-from-ubuntu-ppa.html)
145 • Google Chrome (stable, beta, and dev)
147 • Heftig's version of Aurora (Arch Linux: https://bbs.arch‐
149 linux.org/viewtopic.php?id=117157)
150 • Icecat
152 • Iceweasel
154 • Inox (https://bbs.archlinux.org/viewtopic.php?id=198763)
156 • Luakit
158 • Midori
160 • Opera (legacy, stable, next, and developer)
162 • Otter-browser
164 • Palemoon
166 • QupZilla
168 • Qutebrowser
170 • Rekonq
172 • Seamonkey
174 • Vivaldi
176 • Vivaldi-snapshot
178 Psd's infrastructure can work in principal with any browser that uses a
180 generic chrome or mozilla, etc. format. User supplied profiles are pro‐
181 vided in /usr/share/psd/contrib/ and can be manually copied to
182 /usr/share/psd/browsers/ if one wishes to sync that particular browser.
183 Make a corresponding entry in the BROWSERS array within the config
184 file. Support for these is unsupported.
185
187 Currently, psd does not support symlinked profiles and will refuse to
188 sync if one is detected. For example, your firefox profile is
189 ~/.mozilla/firefox/f8cv8bfu.default but you have moved that directory
190 to /foo/bar/f8cv8bfu.default and replaced it with symlink:
191 $ ls -l ~/.mozilla/firefox
193 lrwxrwxrwx 1 facade users 26 Oct 1 17:02 f8cv8bfu.default -> /foo/bar/f8cv8bfu.default
194 Running psd in preview mode will end in an error informing you of this:
196 $ psd p
198 Warning!
200 /home/facade/.mozilla/firefox/f8cv8bfu.default appears to be a symlink but these are not supported.
201 Please make the browser profile a live directory and try again. Exiting.
202 A proper work around for firefox is to simply edit ~/.mozilla/fire‐
204 fox/profiles.ini defining the canonical path there. One also needs to
205 adjust the IsRelative flag like so:
206 [Profile0]
208 Name=default
209 IsRelative=0
210 Path=/foo/bar/f8cv8bfu.default
211 Other solutions may exist for other browsers but documenting them all
213 here is out of scope.
214
216 Since psd is just a bash script with a systemd service, it should run
217 on any flavor of Linux running systemd. Several distros provide an of‐
218 ficial package or user-maintained option to install psd. One can also
219 build psd from source. See the official website for available packages,
220 dependencies, and installation instructions
221
223 Q1: What is overlayfs mode?
224 A1: Overlayfs is a simple union filesystem mainlined in the Linux ker‐
226 nel version 3.18.0. When used with psd, a reduced memory footprint and
227 faster sync operations can be realized. The magic is in how the overlay
228 mount only writes out data that has changed rather than the entire pro‐
229 file. The same recovery features psd uses in its default mode are also
230 active when running in overlayfs mode.
231 See the example in the PREVIEW MODE section above which shows a system
233 using overlayfs to illustrate the typical memory savings. Note the
234 "overlayfs size" report compared to the total "profile size" report for
235 each profile. Be aware that these numbers will change depending on just
236 how much new data is written to the profile, but in common use cases,
237 the overlayfs size will always be less than the profile size.
238 Q2: How do I enable overlayfs mode?
240 A2: First, be sure psd is not active or else any changes to the config
242 file will be ignored until it is restarted. Overlayfs mode is enabled
243 with the USE_OVERLAYFS= variable which should be set to "yes" in the
244 config file. Psd will automatically detect the overlayfs version avail‐
245 able to the kernel if it is configured to use one of them. It is recom‐
246 mended to run psd in preview mode to verify that the system can in fact
247 use overlayfs.
248 Users wanting to use overlayfs mode MUST have sudo rights without pass‐
250 word prompt to /usr/bin/psd-overlay-helper or global sudo rights with‐
251 out password prompt. If the user does not have global rights, add the
252 following line to /etc/sudoers after any other lines defining sudo ac‐
253 cess. It is recommended to use /usr/bin/visudo as root to set this up:
254 foo ALL=(ALL) NOPASSWD: /usr/bin/psd-overlay-helper
256 Q3: Why do I have another browser profile directory "foo-back-ovfs"
258 when I enable overlayfs?
259 A3: The way overlayfs works is to mount a read-only base copy (so-
261 called lower dir) of the profile, and manage the new data on top of
262 that. In order to avoid resyncing to the read-only filesystem, a copy
263 is used instead. So using overlayfs is a trade-off: faster initial sync
264 times and less memory usage vs. disk space in the home dir.
265 Q4: I need more memory to accommodate my profile/profiles in
267 /run/user/xxxx. How can I allocate more?
268 A4: The standard way of controlling the size of /run/user/ is the Run‐
270 timeDirectorySize directive in logind.conf (see the man page for
271 logind.conf for more). By default, 10% of physical memory is used but
272 one can increase it safely. Remember that tmpfs only consumes what is
273 actually used; the number specified here is just a maximum allowed.
274 Q5: My system crashed for some reason and psd didn't sync back. What do
276 I do?
277 A5: The "last good" backup of the browser profile/profiles should be
279 the filesystem. Upon restarting psd (on a reboot for example), a check
280 is performed to see if the symlink to the tmpfs copy of the profile is
281 invalid. If it is invalid, psd will snapshot the "last good" backup be‐
282 fore it rotates it back into place. This is more for a sanity check
283 that psd did no harm and that any data loss was a function of something
284 else.
285 Q6: Where can I find this snapshot?
287 A6: It depends on the browser. The snapshot will be located in the same
289 directory as the browser profile and it will contain a date-time-stamp
290 that corresponds to the time at which the recovery took place. For ex‐
291 ample, a chromium snapshot will be ~/.config/chromium-backup-crashre‐
292 covery-20130912_153310 -- of course, the date_time suffix will be dif‐
293 ferent.
294 Q7: How can I restore the snapshot?
296 A7: Follow these steps:
298 1. Stop psd.
300 2. Move the "bad" copy of the profile to a backup (don't
302 blindly delete anything).
303 3. Copy the snapshot directory to the name that browser ex‐
305 pects.
306 Example using chromium:
308 1. systemctl --user stop psd.service
310 2. mv ~/.config/chromium ~/.config/chromium-bad
312 3. cp -a ~/.config/chromium-backup-crashrecov‐
314 ery-20130912_153310 ~/.config/chromium
315 At this point, launch chromium which will use the backup snapshot just
317 copied into place. If all is well, it is safe to delete ~/.con‐
318 fig/chromium-bad and the snapshot. Remember, to start psd, no browsers
319 must be open (or psd will refuse to start).
320 Q8: Can psd delete the snapshots automatically?
322 A8: Yes, run psd with the "clean" switch to delete snapshots.
324
326 Users wishing to contribute to this project, should fork it and send a
327 pull request. Source is freely available on github.
328
330 Discovered a bug? Please open an issue.
331 • Several cases of data loss have been reported when using
333 eCryptFS and psd, therefore until this issue is flushed out,
334 users of eCryptFS are encouraged not to use psd unless will‐
335 ing to help troubleshoot suspected browser corruption. See:
336 https://github.com/graysky2/profile-sync-daemon/issues/158
337
339 • Project page: https://github.com/graysky2/profile-sync-daemon
340 • Wiki page: https://wiki.archlinux.org/index.php/Profile-sync-daemon
342
344 graysky (graysky AT archlinux DOT us)
345 02 October 2023 profile-sync-daemon(1)