Change the value of the following lines

GtkScrollbar::has-backward-stepper = 1
GtkScrollbar::has-forward-stepper = 1
GtkScrollbar::stepper-size = 13
GtkScrollbar::slider-width = 13

in /usr/share/themes/Adwaita/gtk-2.0/main.rc

and comment off

# Disable arrows for qt in scrollbars
# image {
# function = ARROW
# detail = “vscrollbar”
# }
# image {
# function = ARROW
# detail = “hscrollbar”
# }

By leizhou, 12. January 2018, 12:15 hr

startxwin — +iglx -nowgl &

in cygwin window,

export DISPLAY=:0.0

ssh -XYC @

then ssh to a node, start fsleyes

This works for me.

By leizhou, 27. October 2017, 08:59 hr

Matlab R2017a can start parpool in text mode but will crash in GUI. The problem is that it is trying to modify a few files in the local toolbox to accommodate the computer specs. If the directory %MATLAB/toolbox/local is readonly, the updated profile will fail writing, and the parpool will still attempt to start on default profile, which crashes since hardware mismatch.

To fix this, you can assign global writing privilege to the %MATLAB/toolbox/local folder, and try again.

By leizhou, 3. May 2017, 13:59 hr

CentOS 7 comes with gcc 4.8.5 but MrTrix needs 4.9+, also it needs Qt-qtsvg
To do this, addition to the mrtrix install instruction:
yum install qt5-qtsvg qt5-qtsvg-devel qt5-qtbase-devel devtoolset-3-gcc.x86_64 devtoolset-3-gcc-c++.x86_64
export QTDIR=/usr/lib64/qt5;export PATH=/usr/lib64/qt5/bin/:$PATH; export CXX=/opt/rh/devtoolset-3/root/usr/bin/g++;
Then you get it.

By leizhou, 28. April 2017, 11:20 hr

In cygwin, if you start X server using command:
$ X -multiwindow -nowgl +iglx &
$ export DISPLAY=:0.0
you will have a GLX functionality over ssh through indirect software rendering

if you start X server using command:
$ X -multiwindow -wgl +iglx &
$ export DISPLAY=:0.0
you will have a GLX functionality over ssh through indirect hardware rendering

In linux system, also, if you start your X interface by running
$ startx — +iglx

your x-interface will accept remote OpenGL rendering

By leizhou, 26. April 2017, 15:48 hr

The current version of GALAXY ( will run into error when using ldaps authentication mechanics. The error is
Traceback (most recent call last):
File “/home/galaxy/galaxy-dist/lib/galaxy/auth/providers/”, line 117, in authenticate
File “/home/galaxy/galaxy-dist/.venv/local/lib/python2.7/site-packages/ldap/”, line 135, in set_option
return _ldap_function_call(None,_ldap.set_option,option,invalue)
File “/home/galaxy/galaxy-dist/.venv/local/lib/python2.7/site-packages/ldap/”, line 66, in _ldap_function_call
result = func(_args,**kwargs)
ValueError: option error
The function in Python LDAP binary func(_args,**kwargs) does not take the option argument “OPT_X_TLS_REQUIRE_CERT” properly.
The CentOS 7 system version of python-ldap binary has the same issue.

To overcome this, you will need to download the python-ldap source from
then install certain devel package using
yum install openldap-devel
then build the source by running
python build
Afterward, you do not need to replace the entire ldap directory, but only overwrite the file in your galaxy/.venv/lib/python2.7/site-packages/ by the file from your build in ./build/lib.linux-x86_64-2.7/ folder.
Then the ldaps will work.

By leizhou, 14. April 2017, 15:54 hr

git clone
yum install python-EnthoughtBase-3.0.5-1.fc14.noarch.rpm
yum install python-matplotlib-qt4 python-matplotlib python-pyside python-configobj
pip install -U pip
pip install -U traits traitsui nibabel pyface
cd melview
python ./ install

By leizhou, 19. January 2017, 16:45 hr

Method 1

openssl passwd -1 -salt xyz yourpass

Method 2

makepasswd –clearfrom=- –crypt-md5 <<< YourPass

Method 3

echo "username:password" | chpasswd

Or you can use encrypted password with chpasswd first generate it using :

perl -e 'print crypt("YourPasswd", "salt"),"\n"'

then later you can use generated password to update

echo "username:encryptedPassWd" | chpasswd -e

this encrypted password we can use to create new user with password


useradd -p 'encryptedPassWd' username

Method 4

echo -e "md5crypt\npassword" | grub | grep -o "\$1.*"

By leizhou, 21. June 2016, 17:07 hr

So do not put matlab runtime into
If yum broken, remove that file and do ldconfig.

By leizhou, 17. June 2016, 16:07 hr

sudo find . -maxdepth 1 -type d ! -name . -exec du -sh ‘{}’ \; | sort -h

By leizhou, 14. June 2016, 16:10 hr


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