Monday, March 19, 2018

Tweaking OpenVPN again

My latest tweaks for OpenVPN is very simple, just add these few lines to the server configure file:

txqueuelen 5000

sndbuf 0
rcvbuf 0
push "sndbuf 0"
push "rcvbuf 0"

And add this line to /etc/rc.local on the server, somewhere before "exit 0":

ifconfig venet0 txqueuelen 10000

Replace venet0 with eth0 etc. if necessary, you can find it out with the ifconfig command. That's all.

The default txqueuelen values are way too small, 100 and 1000, for OpenVPN and Linux OS for today's network bandwidth. I saw lots of dropped packets (again, using the ifconfig command). My OpenVPN is used over LTE/4G mobile network, 5000 is enough. The Linux server is on a 10 Gigabit Ethernet, 10000 is about right. The network is significantly smoother than before.

The "tcp-nodelay" option is good for reducing latency, a good thing for VoIP and gaming.

By setting the buffers to 0, OpenVPN will let the OS do the job. The default values are way too small. This is the major boost to speed, from 5Mbps to 20Mbps.

Thursday, February 22, 2018

Keep Oral-B always in full power

If you are an Oral-B user, you should have noticed that the brush becomes not so powerful if it is fully charged - after the green light is off.

So I use a timer to charge it only before and after the time I use it. For example, I brush around one o'clock at night so I set it to start charging at 10PM and turn it off at 2AM. About 4 hours. Similar for the morning, for another 4 hours.

Then I simply leave it in the charger all the time after each use. This way, the brush is still being charged when I use it and it is always in its full wings.

Depending on how many minutes you brush every time, you may set the total charging time anywhere from 5 to 10 hours. The key is to give it enough time to charge but never be fully charged before you use it. I brush for about 5 minutes each time and 4 hours (8 hours per day) is about perfect.

Saturday, December 30, 2017

Battery replacement for Japanese rice cookers

The battery in some Japanese rice cookers will run out in about 10 years. Unfortunately this battery is solder-on and thus not replaceable by the user. Therefore I had to desolder the old battery and mount a 2-AAA battery holder. From now on, the two AAA batteries should last forever. If they somehow will run out again, it is very easy to replace.

Wednesday, December 13, 2017

Friday, December 1, 2017

Final fix for water in canister

If your Toyota or Scion car has check-engine light on after driving in heavy rain, you may watch this videos for diagnosis (ignore the condom part, no need to do that, because water did not get in from there, see the correct fix at the bottom of this page):

And this video for purging water out of the canister pump module:

For the permanent fix, block the small holes under the gas-feed inlet (take off the rear tire at the driver side and look up):

Tuesday, November 21, 2017

Piaggio/Vespa scooter regulator test and replacement

The battery on my Piaggio LT150 is no longer charged while riding. It took me quite a while to figure out how to access the charging unit, turned out to be quite easy as showing in this video:

This video also shows how to test the regulator, replace it and mount everything back.

Friday, July 7, 2017

How to make headphones comfortable

It is summer time, your headphones become hot and sweaty. Here comes the fix: