Monitorix on ReadyNAS, part 2

The default Monitorix installation (see previous post) puts the log and database files in /var/lib/monitorix/, which is part of the root partition. This partition is only 4 GB in size, and when it is 80% full the NAS sends an email to the admin email address:

System volume ‘root’ usage is 81 %. This condition should not occur in normal conditions. Please contact technical support.

Ouch… Well, it is easy enough to move the log and rrd files to a better location. As this problem is likely to occur for most software installed on the NAS, I decided to make a directory /home/admin/from_root, where things that originally lived on the root partition can be moved.

First su to become root, then stop the monitorix service:

[code language=”bash”]

service monitorix stop


Edit /etc/monitorix.conf using your favourite editor (vim, nano, emacs…). The beginning of mine (where the paths are defined) now looks like this:

[code language=”text”]

# Monitorix – configuration file
# See monitorix.conf(5) manpage for a detailed description of each option.

title = Place a title here
hostname = RN312
theme_color = black
refresh_rate = 150
iface_mode = graph
enable_zoom = y
netstats_in_bps = n
disable_javascript_void = n
temperature_scale = c

base_dir = /usr/share/monitorix/
#base_lib = /var/lib/monitorix/
base_lib = /home/admin/from_root/monitorix
base_url = /monitorix
base_cgi = /monitorix-cgi

enabled = n
host =
port = 8080
user = nobody
group = nogroup
log_file = /home/admin/from_root/monitorix/log/monitorix-httpd
hosts_deny =
hosts_allow =
enabled = n
msg = Monitorix: Restricted access
htpasswd = /var/lib/monitorix/htpasswd
# Log files pathnames
# —————————————————————————–
log_file = /home/admin/from_root/monitorix/monitorix
secure_log = /var/log/secure
mail_log = /var/log/maillog
milter_gl = /var/milter-greylist/greylist.db
imap_log = /var/log/imap
hylafax_log = /var/spool/hylafax/etc/xferfaxlog
cups_log = /var/log/cups/page_log
ftp_log = /var/log/proftpd/access.log
fail2ban_log = /var/log/fail2ban.log
spamassassin_log = /var/log/maillog
clamav_log = /var/log/clamav/clamav.log
cg_logdir = /var/CommuniGate/SystemLogs/
squid_log = /var/log/squid/access.log

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Now that this is done, move the existing files to the new location:

[code language=”bash”]

mkdir /home/admin/from_root/

mkdir /home/admin/from_root/monitorix

cp /var/lib/monitorix/* /home/admin/from_root/monitorix


Almost there. Before starting the service again it is useful to monitor the application’s log file. Make sure you have two shells running side by side. In one of them start a tail of the log file:

[code language=”bash”]

tail -f monitorix -n 50


Now start the service again, using the second shell. You can now monitor the startup log entries, and if all goes well there will be no (serious) errors.

[code language=”bash”]

service monitorix start


Reverse engineering Macbook Air FaceTime camera, part 1

A severely cracked 13″ Macbook Air display came my way some time back. The LCD panel was obviously damaged, but it would be interesting to see what makes such a great display tick, and maybe parts of it could still be used? I believe the display came from a Late 2010 Macbook Air (which would indicate an A1369 type construction), but can’t be sure. Anyway – ideas included

  • Keeping the back lighting (assuming it works) and camera, mounting the whole display on a flexible arm next to the work bench. Given the high intensity of the back lighting, it could then (maybe) provide ambient lighting AND video recording of whatever was being worked on. Maybe with a LED light and camera on a separate flexible arms.
  • If the LED backlighting drivers were toast, there should still be some nice white LEDs in there for scavenging.
  • Same thing for the camera, I believe it to be a 640×480 pixel device, nothing too exiting but could still be useful.

Turns out it’s not entirely easy to disassemble these displays. They are sealed together with very strong tape. Heating the bezel helps a lot, but it’s still a fair amount of work – and given the delicate components beneath the bezel, you might want to think twice before doing this on a laptop you care about.. Some good instructions found here, btw. Results so far:

2013-02-19_10-41-22_smallPrying the bezel open…

…before applying heat with a hot-air SMD rework station (regular heat gun would probably also work, if you are careful):

Voila! Bezel is free:

Now the tricky part. The cable from the cable is a thin wire with some kind of textile cover, for strengths I assume. It goes through the hinges and there is no way (as far as I can tell) to get the cable through there, without cutting off the (very small) connector that normally connects to the computers Left I/O (a.k.a. LIO) board. Cut.

Now the whole camera assembly can be removed. It also includes the ambient light sensor, which communicates over I2C. Unknown protocol for that one though – one for the future to investigate..

Very tiny 6-pin connector, normally going to the LIO board.
2013-02-19_13-11-34_smallCamera module exposed in the top part of the screen. Held in place with 2 small screws.

2013-02-23_22-32-08_smallCamera board. 

2013-02-19_13-17-59_smallThese things are small – fingers included for scale reference.

With six wires in the cable it’s pretty clear that 4 are for USB (+5V, Gnd, Data+, Data-) and 2 for I2C. That cable is however crazy small – it’s about 2 mm diameter. Once the outer layer is off, you see 6 even thinner cables. 2 are black, 4 transparent. Which ones are which?

Google is your friend. Turns out there are schematics to be found if you Google long enough. Turns out you need schematics for the LIO board though, in order to get the pinout of the camera/ALS cable, and it’s nowhere to be found for the A1369. Did find a schematic for the A1370 model though (same computer but 11″ screen), with a bit of luck that cable is the same between models.

The 2 black ones are prime candidates for +5V and Gnd. Cutting away the insulation revealed that the cables are shielded, with a center wire that is barely visible to the eye. It took several attempts before I had separated the wires from the sheilding, and then done the same with the other 4 wires. Soldering these onto an old USB cable was then easy (but ugly!!):


Still, it doesn’t work. The camera is not recognised on an iMac with latest OSX, nor on a Windows 8 laptop. Happened to have a Raspberry Pi lying on the work bench, tried it too with same result: nothing.

But wait… doing a “tail -f /var/log/messages” on the RPi showed that it DID recognise the camera, but that the camera wanted more power than a non-powered USB hub could provide! Placing the camera into the RPi’s regular USB port made it appear nicely when doing a “lsusb” command.

Still, it didn’t work when I connected the camera to the Windows or iMac machines – strange.

Also, the RPi loose contact with the camera after a while – no idea why. Could maybe be a bad USB cable (it’s from an old mouse using USB 1.1 – maybe that’s a problem??), or is there too much noise introduced by the ugly splicing of cables that I’ve done? No idea… More investigation needed. Anyway, the camera enumerates with USB id 05ac:850a, which indeed is an Apple FaceTime camera – nice!