Java does not work in latest firefox 52?

Mar 10th, 2017 | Filed under java

Old problem comes back due to different reasons. Firefox follows chrome and drops support for NPAPI plugins (it affects Silverlight and Flash as well).
By default support is disabled, but you can revert in.

  1. Go to about:config settings webpage (type it as uri in browser and press enter)
  2. Add new entry of boolean type with name plugin.load_flash_only and value set to false
  3. Restart browser and your java and silverlight should work again!

Ubuntu 16.04 custom kernel and latest Virtualbox

Dec 30th, 2016 | Filed under Uncategorized

Due to some reason I had to go with 48 kernel and not 4.4 default one.
After some time I realized that my virtualbox is no longer working… This is one of nice things with Ubuntu.. It works all together flawlessly until you start messing with it (for instance when you need latest software and latest software usually has dependencies on some other latest software).
So for Kernel 4.8 you need Virtualbox 5.1 to install it quickly

wget -q -O- | sudo apt-key add -
wget -q -O- | sudo apt-key add -
sudo apt-get update
sudo apt-get install virtualbox-5.1

Reason: Failed on SHA256 verification on gentoo

Oct 23rd, 2014 | Filed under gentoo, problems

One reason of

Reason: Failed on SHA256 verification

is that during creation of ebuilds some packages are fetched from external sources (for instance from adobe-flash site) and they sometimes publish new version of a package exactly under the same name.
Then next update results in a checksum error, because saved source from distfile directory is used.

To fix that you could:

rm -rf /usr/portage/www-plugins/adobe-flash/


fix it with
ebuild /usr/portage/www-plugins/adobe-flash/adobe-flash- clean prepare

Above situation should occure very rarely.


How to install and configure TL-WN722N on gentoo

Jun 29th, 2014 | Filed under gentoo, problems

1. First make sure you have these options compiled into kernel


If you cannot find them within your config it means that some other dependencies are missing from your kernel.
You can find it more easily with “make xconfig” and selecting option “show all”
2. Most likely you will have to select:


Without these two you will receive a lot of fancy errors like:

ioctl[SIOCSIWPMKSA]: Invalid argument

3. If you will see warning related to RFKILL you can fix them by compiling RFKILL into your kernel and emerge rfkill as well.


After that you can check status of your device by:

rfkill list all

and if it’s blocked just unblock it by

rfkill unblock wifi

Ok.. now iwconfig should show some info about your device.
The only thing left is to confiugre /etc/wpa_supplicant/wpa_supplicant.conf file

for most common WPA2 configuration it should contain :

pairwise=CCMP TKIP
group=CCMP TKIP WEP104 WEP40

If you want to avoid having password in plaintext you can use command
wpa_passphrase yourSsid password

and then paste

(note missing quotes!)

Now is time to check your configuration:

wpa_supplicant -iwlan0 -dd -Dwext -c/etc/wpa_supplicant/wpa_supplicant.conf

If everything works do

ln -s /etc/init.d/net.lo /etc/init.d/net.wlan0

and add it to default runlevel

rc-update add  net.wlan0 boot

In case of problems check:

  1. Is your card visible by lsusb ?
  2. Do you have any errors in dmesg
  3. Did you rebooted after recompiling modles?

I didn’t have to download anything drivers from suspicious pages! So please do not do this!
Everything worked on a modern kernel 3.13.7

Other common samples of wpa_supplicant.conf configurations related to different router’s security settings can be found here:


Public key for jenkins is not installed

Apr 18th, 2014 | Filed under Uncategorized

Just do:

sudo wget -O /etc/yum.repos.d/jenkins.repo
sudo rpm --import

sudo yum install jenkins


How to update all kde packages without others on gentoo.

Feb 20th, 2014 | Filed under gentoo
Try emerge -u $(qlist -IC kde-base/)

hwclock: Cannot access the Hardware Clock via any known method.

Dec 26th, 2013 | Filed under gentoo, problems

Recently I was updating my comp of course there was a need to make some kernel changes (I switched to Intel i5-4570 ), but most of things went rather smoothly, but I had problems with time during dual boot.

hwclock: Open of /dev/rtc failed: No such file or directory
No usable clock interface found.
hwclock: Cannot access the Hardware Clock via any known method.

Checking kernel settings wasn’t obvious to me, cause dual boot was working previously and I though I moved previous kernel config..

Anyway RTC support was not included in kernel.. now I have:

# RTC interfaces
# I2C RTC drivers
# SPI RTC drivers
# Platform RTC drivers
# on-CPU RTC drivers
# HID Sensor RTC drivers

Some of settings may be not needed for you, but that’s my conf.
After recompiling and installing kernel error is gone.


How to attach Java src jar’s to Eclipse on Macbook

Sep 5th, 2013 | Filed under java, mac

How to attach Java src jar’s to Eclipse

Go to:
cd /System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK/Home

Find the src.jar there:
find /Library/Java -name ‘src.jar’

And link whatever you will find in current directory
$ sudo ln -s /Library/Java/JavaVirtualMachines/1.6.0_51-b11-457.jdk/Contents/Home/src.jar .


Increasing limit of open files in linux

Sep 5th, 2013 | Filed under gentoo

Sooner or later when doing some bigger system or just by messing with os you will meet that error:

Too many open files

You can solve it quickly by:

vi /etc/sysctl.conf
Append a config directive as follows:
fs.file-max = 200000
Save and close the file. Users need to log out and log back in again to changes take effect or just type the following command:
# sysctl -p
Verify your settings with command:
# cat /proc/sys/fs/file-max

 vi /etc/security/limits.conf
Set admin user (or for any other user) soft and hard limits as follows:
admin soft nofile 200000
admin hard nofile 200000



kdepimlibs compilation problem

Feb 8th, 2013 | Filed under gentoo, problems

Having folowing problem during update to kde-4.10 ?

/var/tmp/portage/kde-base/kdepimlibs-4.10.0/work/kdepimlibs-4.10.0/kldap/ldapconnection.cpp:268:80: error: ‘ldap_init’ was not declared in this scope
/var/tmp/portage/kde-base/kdepimlibs-4.10.0/work/kdepimlibs-4.10.0/kldap/ldapconnection.cpp: In member function ‘void KLDAP::LdapConnection::close()’:
/var/tmp/portage/kde-base/kdepimlibs-4.10.0/work/kdepimlibs-4.10.0/kldap/ldapconnection.cpp:359:27: error: ‘ldap_unbind’ was not declared in this scope



to /etc/make.config