Getting Started on Universe (Cosmos and Eric)

This document briefly addresses the following issues:

• accessing Cosmos and Eric from the PC Centres, office and home machines;
• usernames and passwords;
• file-transfer;
• using X-Windows;
• home-directories, scratch-space and disk-quotas;
• getting help on Cosmos/Eric;
• the multi-user aspects of the machines (permissions, sharing resources with others);
• long-running jobs and batch-systems;
• problems;

Universe can be accessed in the normal way using SSH and, if required, X Windows. (Access via Telnet and the "r-commands" has been blocked for security reasons.)

Both Cosmos and Eric are globally-accessible.

Much more information on accessing Cosmos and Eric can be found in the separate document Accessing Universe.

...from Campus PC Centres

From the Start menu choose

    Start->Programs->Unix Connectivity->Cosmos->Secure Shell Client
    Start->Programs->Unix Connectivity->Cosmos->Secure File Transfer Client

    Start->Programs->Unix Connectivity->Cosmos->Secure Shell Client - X windows

...from other MS Windows machines

Recommended clients to be used and/or installed for Microsoft Windows are:

• For SSH, the client from SSH Communications Security (v3.2 or above) and PuTTY (v0.52 beta or above).
• eXceed which provides X Windows functionality (available from the ISD Helpdesk).

...from Linux, Solaris and other Unix machines

Virtually all Unix (Linux and Solaris) boxes come with SSH and X-Windows clients and these are usually satisfactory. The OpenSSH client has suffered a number of bugs recently so that from SSH Communications Security is recommended in its place.

To access Universe machines, users should use their eUMIST usernames and passwords.

Usernames cannot be changed. Passwords may be changed by visiting the ISD web site --- changes should take effect almost immediately. (Passwords cannot be changed by use of passwd or yppasswd whilst logged into Cosmos/Eric.)

Files may be transfered to and from Cosmos and Eric using SCP and/or SFTP in the usual way. (Standard FTP and "r-command" access has been blocked for security reasons.)

X Windows can be used to have processes (applications) which are running on a remote machine (host) display on the local machine (host). For example, you can have Abaqus run on Eric whilst the programme is displayed on your local Linux desktop. To do achieve this:

1. Ensure that you SSH client is configured to tunnel X11 connections.
   
   
2. SSH into Cosmos/Eric. Ensure that the DISPLAY environment variable is set to something like cosmos:11.0 or eric:12.0 --- do not set or export the DISPLAY environment variable yourself, it should be determined by SSH automatically (if it is not, then it is likely that your SSH client is not configured to tunnel X11 connections).
   
   
3. Start your X-client in the normal way, e.g., emacs &; after a few moments it should appear on your (local) desktop.

Some users will be used to setting the DISPLAY environment variable on the remote machine manually, e.g., remote> setenv DISPLAY mymachine.domain.ac.uk or remote> export DISPLAY=mymachine.domain.ac.uk and giving permission, on their local machine, for an X-client to connect, e.g., local> xhost cosmos.umist.ac.uk. This is both unnecessary and discouraged when using SSH (but was necessary with Telnet and rlogin). Setting DISPLAY and using xhost means that the X-client on the remote machine connects to your local machine via a new connection (on port 6000) which is not encrypted or secure. However, such connections may prove noticeably faster for graphics-intensive clients. Use of these faster, but insecure connections is permitted on Cosmos/Eric at the time of writing (January, 2004) but may be blocked in the future.

For more information, see the separate document Accessing Cosmos.

Most users of Cosmos and Eric have a single home-directory which is shared between the machines --- they see the same files whichever machine they login to. A quota system is enforced on this space. As a user approaches their quota limit they will see warning messages and should delete or compress some files. Each user has both a soft and hard limit: breaching the soft limit results in warning messages; breaching the hard limit will lead to data loss. Reasonable requests for an increase in quota can usually be accommodated. To check quota limits and disk usage type

  quota -v

In addition to their home-directory, users have a (larger) quota in /scratch. This space is intended for temporary storage of data, for example that produced by running computational jobs; it should not be used for long-term storage. Files not associated with a running process are liable to removed from /scratch without notice.

Users who have accounts on Eric dating from before the machine became open to all staff and students will see their original disk-space, not that from Cosmos. If these users would like to see both spaces they should contact ISD Helpdesk.

There are several sources of help on commands, utilities, applications, etc., on Universe:

• All Unix (Solaris and Linux) systems have a man system which offers help with built in utilities, and often, installed third-party applications, for example man xclock.
  
  
• Web pages documenting many of the applications and utilities available on Universe are available by following the appropriate links from www.umist.ac.uk/isd/unix.
  
  
• Web pages offering general Unix-related help and information can be found by following the links from the main ISD Unix page.
  
  
• If none of the above are sufficient, further help can be obtained by contact the ISD Helpdesk --- please make clear that your query regards Cosmos/Eric.

Both Cosmos and Eric are multiuser machines, i.e., many people can be logged in and using resources simultaneously. We ask that users be considerate in their usage of memory and CPUs. Do not hog a machine --- we are watching you! (The simplest way to check your usage against others' is to use the top command --- /usr/local/bin/top.)

Both Cosmos and Eric have the NQS batch/queue system installed and available to all users. This must be used for all long-running, computationally-intensive jobs --- such jobs found to be running outside of NQS may be killed without notice. (Short, e.g., a few hours, computationally-intensive interactively-run jobs are tolerated.)

Eric is particularly suited to jobs which require a lot of memory.

See the document dedicated to NQS for more information.

If you have problems accessing or using Universe please contact the ISD Helpdesk making clear in your query that the problem concerns Cosmos/Eric.