Differences

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--- access [2023/09/13 09:31] – [Private servers] olivier
+++ access [2025/12/01 14:40] (current) – [X2GO] olivier
@@ Line 13: / Line 13: @@
 Once connected to the server, you will be presented with a Linux command line.  If unfamiliar with the Linux environment, here is a link to a [[https://ubuntu.com/tutorials/command-line-for-beginners|quick guide]] that covers the basics of Linux shell operation.
+To use Key access, refer to the following page: [[access:sshkeys| Using SSH Keys]]
 ==== Private servers ====
-Some CIM computers are on a private (internal) McGill vlan (10.69.54.0/23).  These servers cannot be accessed directly from the internet.  To access these computers, you can use any public CIM server as an ssh jump host.  (SSH jump hosts are a way to proxy ssh connections through one server to access another)
+Some CIM computers are on a private (internal) McGill vlan (10.69.54.0/23).  These servers cannot be accessed directly from the internet.  To access these computers, you can use the McGill vpn to get on the McGill network, or you can use any public CIM server as an ssh jump host.  (SSH jump hosts are a way to proxy ssh connections through one server to access another)
 The command to connect to a private CIM computer is:
 <code>
-ssh -j <CIMUSERNAME>@barn.cim.mcgill.ca <CIMUSERNAME>@<PRIVATESERVER>.cim.mcgill.ca
+ssh -J <CIMUSERNAME>@barn.cim.mcgill.ca <CIMUSERNAME>@<PRIVATESERVER>.cim.mcgill.ca
 </code>
@@ Line 30: / Line 30: @@
 ==== PuTTY ====
-If you are on another type of operating system, we suggest using an ssh client such as [[https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html|PuTTY]] to connect to CIM computers.
+The Windows commandline now includes an SSH client, but if you routinely log into a remote system from your Windows machine we recommend using an SSH client such as[[https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html|PuTTY]] to connect to CIM computers.
 When you open PuTTY, you'll be presented with a configuration screen where only two options need to be configured, the server address (barn.cim.mcgill.ca) and the connection type (SSH).
@@ Line 40: / Line 40: @@
 === Private servers ===
 To access private CIM servers, you'll need to configure an SSH proxy in PuTTY.  To do so, you'll need a version of putty >0.77 and navigate to ''Connection > Proxy'' and select SSH as the proxy type and specify the details of the jump host (barn.cim.mcgill.ca).
+==== X2GO ====
+For remote desktop access to CIM servers, you can use x2go. (most CIM servers should be setup for it, but please contact us if a machine does not have the x2go server installed)
+To use x2go, you will need the x2go client install on your local machine.  You can download the client from the [[https://wiki.x2go.org/doku.php/download%3Astart|x2go website]], or if you are on a linux machine, there should be a x2goclient package available.  For example, on debian-based systems, the following will install the client:
+<code>
+# sudo apt-get install x2goclient
+</code>
+Once the client is installed, you can configure the connection with the following settings: (change the login to your username and the host from barbados.cim.mcgill.ca to the machine you want to connect to)
+{{ ::x2go.png?direct&400 |}}
+Once the connection is configured, you should be able to connect and use the remote desktop.
+{{ ::x2go2.png?nolink&400 |}}
+If you need to use the GPU for graphical applications, the configuration is more involved and will require intervention from us to set the server up to allow it.
 ===== File Access =====
@@ Line 55: / Line 75: @@
 It is also possible to define an ssh jump host to the scp commands by adding ''-j <CIMUSERNAME>@barn.cim.mcgill.ca'' to access files located locally on private servers.
+==== sshfs ====
+To mount directories with sshfs, while going through a jump host, the following command can be used:
+<code>
+sshfs -o ProxyJump=<cimUsername>@barn.cim.mcgill.ca <cimUsername>@<computerHostname>.cim.mcgill.ca:/home/<filesystem>/<directory> <localMountTarget>
+</code>
+If you prefer defining the jump host in your ssh_config file for more convenient access, you should specify the jump host and the target hostname separately, as such:
+<file>
+Host barn
+  HostName barn.cim.mcgill.ca
+  User <cimUsername>
+Host <computerHostname>
+  HostName <computerHostname>.cim.mcgill.ca
+  ProxyJump barn
+  User <cimUsername>
+</file>
+You can then use the following command to mount remote directories:
+<code>
+sshfs <computerHostname>:/home/<filesystem>/<directory> <localMountTarget>
+</code>
 ==== Filezilla ====
@@ Line 64: / Line 109: @@
 Set the protocol to ''SFTP'', the host to ''barn.cim.mcgill.ca'' and set your username.  You can then click ''Connect'' to connect to the CIM server.  You will then be able to access and transfer files.
+===== Sudo on CIM Workstations =====
+> "With great power comes great responsibility..." - Uncle Ben, Spiderman
+> "God, root, what is difference?" - Pitr, User Friendly
+Generally speaking, users do not have sudo/root access on CIM workstations. This is because, unlike Windows or MacOS, Linux gives much more power to the user. Windows will give you warnings and/or prevent you from erasing critical system files, whereas if you use sudo carelessly, Linux will delete the running kernel without so much as a warning.
+Things to consider as a user with sudo:
+  * sudo is the same as root which is the same as administrator.
+  * sudo can be used to break your system. If you share your system with other users, you can/will break the system for them too.
+  * If in doubt, ask us before trying something. Some things on CIM systems are done for a reason, or are configured in a specific way. There is often a reason for this.