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→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 Seneca 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.
{{Admon/tip|Check Your Key!|Your professor uses an automated script to create accounts, so the key must be valid, in the OpenSSH format, and correctly named in order to work successfully.}}
== 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.}} {{Admon/important|Server Changes|The server configurations have changed several times -- previous mentions of these systems by name may have referred to different hardware. Note that servers may be added or removed as the semester proceeds.}} --> The names of servers within CDOT are based on the names of countries. There is no significance to the country names. === AArch64: aarchie israel.cdot.systems ===The current [[ARMv8]] A main 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
If you're using a command-line ssh system, you can issue a command such as this:
ssh -p 2205 ''username''@ehl.cdot.systems === AArch64: israel === A different AArch64 system is ''israel''. This machine has a good number of mid-level cores. This system is located outside of the EHL and can be reached directly: ssh ''username''@israel.cdot.systems--> === x86_64: portugal.cdot.systems === The x86_64 server system is known as ''portugal''. If you're using a command-line ssh system, you can access xerxeswith a command such as this: ssh ''username''@portugal.cdot.systems
== 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"
port 2200
Host "bbetty"
hostname "ehl.cdot.systems"
user "YourUserID"
port 2202
Host "ccharlie"
hostname "ehl.cdot.systems"
user "YourUserID"
port 2205
Host "xerxes"
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 xerxesportugal You can similarly configure simplified access in most other SSH client programs.
== SSH Multiuser Access from Other Clients ==
{{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!
== 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.