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Subsections

Getting started


Web Administration Account

All users of the service must first register with HPCx via the HPCx web site. To do this, users will need the project code and password provided by their project Principal Investigator (PI) or supervisor. If the PI does not have these, the PI needs to contact the HPCx Helpdesk. The email address is:

support@hpcx.ac.uk

Once you have the project code and password, go to the HPCx web site at:

http://www.hpcx.ac.uk/projects/

and follow the instructions for new user registration. Users will be asked to provide a preferred e-mail address which will act as a unique identifier for HPCx administration. All communication with the user will be via this e-mail address, so it is essential that it is kept up-to-date. This is the user's responsibility.

Once the registration form is submitted, both the user and the project PI will receive an e-mail to that effect. Once confirmation of the registration from the PI has been received, an administration account will be created. The user will then receive a further e-mail with details of the account and initial password.

If encountering a delay between registration and receipt of account details, please check first with the project PI: it is their responsibility to confirm the registration. The process should usually take 1-2 working days.

Please report any problems with the web-site to:

support@hpcx.ac.uk

See here and here for more details of the web-site.

Machine accounts

It is important to realise that users will need to register for a web administration account before receiving a login account and password for the service machine. The former is used to access administration services via the web site, while the latter is a normal machine login account. The two should not be confused.

Machine accounts are requested via the web administration pages; again, go to:

http://www.hpcx.ac.uk/projects/

and follow the instructions.

Logging in

Users can log into the HPCx front end via ssh (and ssh only). For example,

$ ssh userid@login.hpcx.ac.uk
userid@login.hpcx.ac.uk's password:

The RSA key finger print of login.hpcx.ac.uk is

b8:01:60:9e:fe:46:67:d3:cf:56:ba:e0:cf:92:65:32.

Note that users will not be able to log into hpcx.ac.uk -- this is not a service machine.

Users wishing to run X11 clients on the HPCx machine should use the -X option of ssh in addition when connecting to the HPCx front end

$ ssh -X userid@login.hpcx.ac.uk

Setting the display manually and using the xhost command to enable X11-traffic from login.hpcx.ac.uk is strongly discouraged for security reasons. When using PuTTy on a Windows machine X11-traffic can be enabled via

Connections > SSH > Tunnels > Enable X11 Forwarding

For security reasons, first-time users will be prompted to change their initial password via the passwd command. Passwords should be at least 6 characters long with at least 1 non-alphanumeric character. Users will not be allowed to re-use an existing password. Passwords will have a maximum lifetime of 6 months, after which a change will be requested.

Please note that you will be logged out of the machine after 5 hours of idle time.

Password changes

There are two sets of circumstances where a password change might be required:

The password is known, in which case the passwd command should be used. This will involve the user in a dialogue which is a little more involved than the usual passwd dialogue and which in fact silently logs the user onto the HPCx Administration Web Site machine. However, this dialogue is self-documenting, and should only take a moment to complete. Once completed, please note that it will take the new password several minutes to propagate through the whole HPCx machine. Note that this is the same dialogue as is used for changing shells, but changing the password is one of the two options presented.

The password has been forgotten, or is unknown for some other reason. In this case, requests for a new password must be made via the `Your User Accounts' section of the HPCx Administration Web Site. See sections here and here for more details of the web-site.

System maintenance

By default, the system is booked for preventative maintenance from 1200 until 2400 on the 2nd and 4th Wednesdays of each month. These slots may not be taken, and if they are, then they may not be for the full duration - a stop/go decision will normally be made by 1200 hrs on the preceding Monday.

Watch the login message for details of these sessions.

Shells, etc.

The HPCx machines run AIX, the IBM version of Unix. The default login shell is the Korn shell (ksh). Users who prefer a different shell may change their login shell by running the chsh command.

This will involve the user in a dialogue which is a little more involved than the usual chsh dialogue and which in fact silently logs the user onto the HPCx Administration Web Site machine. However, this dialogue is self-documenting, and should only take a moment to complete (in fact it is the same dialogue as is used for changing passwords, but changing shell is one of the two options presented).

Currently available supported shells are:

bsh
bash
csh
ksh

Users are requested to restrict their choice of shell to this list.

Transferring files

File transfer to and from the HPCx machine must be achieved via scp or sftp. For example:

userid1@host$ scp template.tar userid2@login.hpcx.ac.uk:.
userid2@login.hpcx.ac.uk's password:
template.tar 100% |*******************************| 5170 00:00
userid1@host$

Transferring large amounts of data to/from HPCx: bbFTP

For a description of using bbFTP to transfer large amounts of data between HPCx and HECToR please see the bbFTP guide on the HECToR website:

http://www.hector.ac.uk/support/documentation/guides/bbftp/

bbFTP is an open-source secure multistreamed file transfer utility, released under the GNU General Public License. It was written by Gilles Farrache at IN2P3 Computing Center in Lyon, France. bbFTP has been optimised for the transfer of large files: it securely authenticates, but then transfers file data in multiple unencrypted streams, thereby avoiding the computational overhead of encryption and decryption. bbFTP also allows large windows as defined in RFC1323, and therefore is well suited to the problem. Previous studies of grid-ftp have shown that there is good scope for improvement over SCP performance. grid-ftp however, requires a non-trivial certificate based authentication mechanism that is often too large a barrier for user uptake. bbFTP allows password or public key based authentication in the same manner as scp, so is immediately accessible to users with minimal setup costs.

bbFTP is available from http://doc.in2p3.fr/bbftp/index.html

Editors

The following text editors are available on the HPCx service machine:

vi
emacs


next up previous
Next: User Resource Management Up: User's Guide to the Previous: Architecture Overview
Andrew Turner
2010-01-14