1,885
edits
Changes
→Common SSH Problems
[[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".
== Available Servers ==
=== x86_64: xerxes ===
ssh ''username''@xerxes.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"
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 "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 aarchie
ssh bbetty
ssh xerxes
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.
== OS Versions ==
Note that the servers may have different operating system releases.
== Backup Your Accounts ==
With other SSH clients:
# Your key must be in OpenSSH format when you send it to your professor; this format is used by the default SSH client on Mac OS/X and Linux as well as PuTTY. If it is in SSH2 format, used by some other client programs, you can convert it with this command on a Linux system with OpenSSH (such as Matrix):
ssh-keygen -i -f ~/.ssh/''SSH2_PUBLIC_KEY_FILE''.pub > ~/.ssh/''OPENSSH_PUBLIC_KEY_FILE''.pub
Your professor will do this automatically as part of the key processing; however, you will need to manually perform this step for any keys that you append to your <code>~/.ssh/authorized_keys</code> file(s).
== 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.
