1,885
edits
Changes
→AArch64: israel.cdot.systems
[[Category:SPO600]]
<!-- {{Admon/important|Backup Your Data|These computers are NEVER backed up. Please save all important files on other storage. '''These machines may fail, be removed , be upgraded, or be reinstalled at any time.'''}}In [[SPO600]], remote access to servers is provided for learning and project work. It is recommended that you also set up [[SPO600 Host Setup|a personal Linux system]].-->
== Preparatory Steps ==
In order to gain access to these computers, you must send an [[SSH]] key to your [[User:Chris Tyler|professor]].<!-- Please follow these instructions exactly:
# Follow the steps outlined under [[SSH#Using_Public_Keys_with_SSH|Using Public Keys with SSH]] to create your key.
# Copy the public key (<code>id_rsa.pub</code> or <code>id_dsa.pub</code>) to a file named <code>''yourUserId''.pub</code> -- for example, if your chosen user ID is "jldoe", save the key in the file <code>jldoejdoe.pub</code> using a command such as: <code>cp ~/.ssh/id_rsa.pub ''jldoejdoe''.pub</code># Attach that file to an e-mail message and send it to [mailto:chris.tyler@senecacollege.ca chris.tyler@senecacollege.ca] with the subject line "SPO600 Key".-->
An account will be created within a few work days of sending the key.
== Available Servers ==
<!-- {{Admon/important|Content being Updated|This page is in the process of being updated from a previous semester's content. The SPO600 servers will be set up in a new configuration later this semester, and this information will be updated. Do not rely on this information until this warning is removed.}}
The current, names of servers within CDOT are based on the names of countries. There is no significance to the country names. === AArch64: israel.cdot.systems === A main [[ARMv8]] AArch64 system is available, known as ''israel''aarchie. This machine has a lot of mid-range cores. You can access this system at the hostname israel.cdot.systems; if you're using a command-line ssh system, you can access israel with a command such as this: ssh '' or username''@israel.cdot.systems<!-- === AArch64: bbetty === Another type AArch64 system is available as 'archie'bbetty''. This machine has a moderate number of low-medium cores. This is a system that is currently located inside the [[EHL]]. To connect to this system, you have to go through the EHL gateway on port 2200.
If you're using a command-line ssh system, you can issue a command such as this:
ssh -p 2200 ''username''@ehl.cdot.systems
ssh -p 2205 ''username''@ehl.cdot.systems
=== x86_64AArch64: xerxes israel ===
The second x86_64 server system is known as ''yaggiportugal'' and . If you're using a command-line ssh system, you can be accessed access xerxes witha command such as this:
== Simplified SSH Access ==
If you're using OpenSSH (the ssh client used on most Linux systems and other platforms), you can simplify complex ssh command lines by placing host connection details in the file <code>~/.ssh/config</code>:
hostname "ehl.cdot.systems"
user "YourUserID"
hostname "xerxes.cdot.systems"
user "YourUserId"
Host "aarchie"
hostname "aarchie.cdot.systems"
user "YourUserID"
Host "bbetty"
hostname "ehl.cdot.systems"
user "YourUserID"
port 2200
Host "ccharlie"
hostname "ehl.cdot.systems"
user "YourUserID"
port 2205
-->
Host "portugal"
hostname "portugal.cdot.systems"
user "YourUserID"
Host "israel"
hostname "israel.cdot.systems"
user "YourUserID"
<!-- Host "xerxes"
hostname "xerxes.cdot.systems"
user "YourUserID"
-->
Once you have added these lines (inserting your user ID where appropriate) and set the permission on that file (<code>chmod 0600 ~/.ssh/config</code>) you can use these commands to access the servers:
ssh aarchieisrael ssh bbetty ssh ccharlie ssh xerxesportugal
You can similarly configure simplified access in most other SSH client programs.
== SSH Multiuser Access from Other Client Systems == Remember that these machines are multi-user systems. Use the <code>w</code> or <code>who</code> commands to see who else is using them; you can also try using the <code>write</code> command to communicate with another user if required. == Passwords ==
{{Admon/caution|Danger! Use Superuser privilege at your Own Risk.|Note that the use of the superuser account via <code>sudo</code> removes almost all restrictions on what you can do. It is easily possible for you to completely destroy the operating system! Take your time, double-check your commands, and if in doubt, ask. Be aware that your actions may affect other users and vice-versa.}}
{{Admon/caution|Do Not DO NOT Build or Install Software Except Via as Root except via RPM (dnf/yum) or DEB (apt)|Do not build or install software as the root user (using <code>sudo</code>), except in RPM or DEB form using the <code>dnf</code>/<code>yum</code> or <code>yumapt</code> commands(as appropriate to the system). Building or installing software as root may overwrite system files and be very difficult to track down.<br /><br />It is OK to install software into your own directories (e.g., <code>~/bin</code> or <code>~/local</code>), which can be done without root privilege.}}
In order to use <code>sudo</code>, you will need to know your password. An initial random password is provided in the file <code>~/password.txt</code> (note that your password will be different on each server). Feel free to change this with the <code>passwd</code> command -- not by editing the file, which is provided only for your information!
== Multiuser SSH Access from Other Client Systems == If you wish to access the servers from additional computers, you can append the SSH public keys from those computers to the <code>~/.ssh/authorized_keys</code> file. Alternately, you can copy the private key from one client system to another (e.g., your laptop to your desktop). == OS Versions ==
# If your SSH public key is not named <code>~/.ssh/id_rsa</code>, your SSH client may not automatically find it. You can specify the identity (private key) file using the <code>-i</code> argument to the SSH command.}}
By reading through the output carefully, you can see what the OpenSSH client program is doing, and address any problems that arise (such as permission or file naming issues).
== Disconnect/Reconnect Ability ==
The [[Screen Tutorial|screen]] utility provides disconnect/reconnect capability, which is very useful for unstable network connections, long interactive operations, and changing your work location.
Other programs such as tmux provide similar capability.
For graphical disconnect/reconnect capability, consider using VNC.