Bureaucrats, cc_docs_admin, cc_staff
2,224
edits
SSH: Difference between revisions
Jump to navigation
Jump to search
Added remarks on the existence of multiple login nodes for the clusters interfering with the use of the "screen" command.
(internal links for PuTTY and MobaXterm) |
(Added remarks on the existence of multiple login nodes for the clusters interfering with the use of the "screen" command.) |
||
| Line 23: | Line 23: | ||
The option <tt>-Y</tt> forwards X11 traffic which allows you to use graphical applications on the remote server such as certain text editors. Note that to use graphical applications you also need to have an X11 server installed on your workstation. Under Linux an X11 server will normally already be installed, but users of OS X will typically need to install an external package such as such [https://www.xquartz.org XQuartz]. Under windows, MobaXterm comes with an X11 server, while for PuTTY users, there is Xming (download [http://downloads.sourceforge.net/project/xming/Xming/6.9.0.31/Xming-6-9-0-31-setup.exe installer] and [http://sourceforge.net/projects/xming/files/Xming-fonts/7.5.0.47/Xming-fonts-7-5-0-47-setup.exe/download extra fonts]). The first time that you connect to a remote server you'll be asked to store a copy locally of its "host key", a unique identifier that allows the ssh client to verify, when connecting next time, that this is the same server. | The option <tt>-Y</tt> forwards X11 traffic which allows you to use graphical applications on the remote server such as certain text editors. Note that to use graphical applications you also need to have an X11 server installed on your workstation. Under Linux an X11 server will normally already be installed, but users of OS X will typically need to install an external package such as such [https://www.xquartz.org XQuartz]. Under windows, MobaXterm comes with an X11 server, while for PuTTY users, there is Xming (download [http://downloads.sourceforge.net/project/xming/Xming/6.9.0.31/Xming-6-9-0-31-setup.exe installer] and [http://sourceforge.net/projects/xming/files/Xming-fonts/7.5.0.47/Xming-fonts-7-5-0-47-setup.exe/download extra fonts]). The first time that you connect to a remote server you'll be asked to store a copy locally of its "host key", a unique identifier that allows the ssh client to verify, when connecting next time, that this is the same server. | ||
Note that when connecting via SSH to a Compute Canada cluster you will be randomly assigned to one of several distinct login nodes used for the cluster to balance the connection load, so that you may well land on a different login node from one connection to another, e.g. <tt>cedar1</tt>, <tt>cedar5</tt>, <tt>gra-login4</tt> or <tt>gra-login2</tt>. If you use a program like [https://www.gnu.org/software/screen/ screen] to manage your login sessions, you will need to make sure that you are on the same login node to open an older session, by making an SSH connection to the appropriate login node from whichever one you initially landed on. If for example I was assigned <tt>gra-login4</tt> when I typed <tt>ssh userid@graham.computecanada.ca</tt> but I want to be on <tt>gra-login2</tt>, I can simply type <tt>ssh gra-login2</tt> from <tt>gra-login4</tt> to get there. | |||
<!--T:4--> | <!--T:4--> | ||