(1) Starting August 2021, remote connection requires a VPN. Instructions:
https://biu365-my.sharepoint.com/:w:/g/personal/noam_biu_ac_il/EQoDoPlkjzlOn5tBqotJX44BxJW9beX9VdWYt14hopTGlg?rtime=RVqnqdRf2Ug
(2) One you are on VPN
From your lab's workstation
ssh -X -l $USER cortex.lnx.biu.ac.il
Similarly you can connect to ctx01.lnx.biu.ac.il, ... ctx19.lnx.biu.ac.il
Use cat/proc/cpuinfo and cat /proc/meminfo to find out about the memory and cpu of each machine.
From home linux machine
ssh -l $USER cortex.lnx.biu.ac.il
From any chrome browser
Use a chrome extension (search). Many extensions use "screen", so you can give your session a name, and can reconnect to the same session after logging out.
From home windows machine, text terminal
putty is a popular windows client.
From home windows machine, graphical interface
Most people in the lab use NX nomachine.
Install their client, and add your name to one of our servers (see separate instructions on this page).
Some people use Xming. See instructions here.
Some reported it was very slow.
Try remotedesktop chrome extension
To list NX users on a machine, first ssh to that machine
ssh -l USERNAME cortex.lnx.biu.ac.il
Then
/usr/local/bin/op nxsrv --userlist USERNAME.
Or use the script source /cortex/code/scripts/list_nx to get all users.
Remove and add users using
/usr/local/bin/op nxsrv --useradd USERNAME
/usr/local/bin/op nxsrv --userdel USERNAME
Currently, only a single user can connect to a machine at a time. The assignments of NX to users is:
machine = cortex, user = gal, noalis
machine = ctx01, user = yuvval
machine = ctx02, user = dorony
machine = ctx03 user = ohadfel, dorony
machine = ctx04, user =
machine = ctx05 user = ortald
Open a terminal inside an NX session and type
xrandr --fb <resolution>
e.g.
xrandr --fb 1900x1080
The problem is probably with your (gnome) session. Try to kill all your processes on that machine, by SSH to the relevant machine and typing:
kill -TERM -1
Warning: this will kill ALL your jobs and processes on that machine!
Restarting NX server on a machine
If you would like to restart the NX server on a machine, SSH to the relevant machine and type:
op nxmng restart
How to develop and debug your application on a remote server
Please see a detailed tutorial on how to debug your application on a remote server using Pycharm:
Using Pycharm on Remote Machine
Execute the server with
1. Connect to a ctx0? machine.
2. Choose a personal DISPLAY NUMBER
3. Copy the following file to your ~/.vnc
cp ~ohadfel/.vnc/xstartup ~/.vnc/xstartup
4. Execute (only once) the command:
/cortex/users/apps/tigervnc-1.8.0.x86_64/usr/bin/vncserver :<DISPLAYNUMBER> -geometry 1650x1000 -localhost
IMPORTANT: Don't forget to set the -localhost option above
5. port forward your machine to 590X where X is the DISPLAYNUMBER
6. connect to the ctx0? machine with a no-machine client
1. From the MobaXterm, open a new SSH session to one of the cortex machines ctx??.lnx.biu.ac.il (replace ?? with machine number)
2. type krdc &
3. Select a new VNC Session
4. type the ip address of your machine:VNCport
5. Enter username and password you selected (you can skip the KWallet application).