Information for CSED Staff using hsl and softeng

These pages contain information on the CSED computing systems and the setup at RAL.

Background

The Numerical Analysis Group and Software Engineering Group run two file/compute servers: hsl.rl.ac.uk and softeng.cse.rl.ac.uk. The intention is that these systems provide identical services: compilers, tools, applications etc. For example f95, the NAG compiler is available on both machines as are MATLAB and mpich. Common files and applications - from /usr/local etc - should be on both machines. Other applications such as the Intel compiler, ifort - found in /opt/intel/fc - should also be replicated. It should be possible to use exactly the same make files on both machines without change.

Essentially softeng mirrors hsl so that if hsl should crash softeng can replace it with a minimum of delay.

User names

All CSED staff can use either machine and will have an identical username (the uid and gid will be same) on each system. This will be generally the username on their local system. Access to the machines is by ssh. For example cg log-in to his local machine should be able to loggin to hsl by typing: ssh hsl.rl.ac.uk. ssh will assume the local username and prompt for the hsl password if required.

Home file systems: /home/<username>

The home file system of each user is the same on both systems (hsl exports /home/<username> to softeng) so that when logging into softeng you will be using your file system on hsl. /home/<username> on either system will contain the sames files - they are the same files! /home/<username> files and directories are mirrored to /softeng/<username>.

Remember, unless this has been specifically setup, /home/<username> on hsl or softeng will not be the same file system as on your local machines or laptop.

File systems on hsl and softeng

The file systems of hsl (excluding /tmp and a few others) and softeng are synchronised throughout the day at: 7.00, 10.30, 12.30, 15.30 and 17.00. So we can view the files on softeng as a dynamic backup of those on hsl.

Files in /home/<username> are mirrored to equivalent directories under /softeng/<username>. You should never alter or add to the directories or files held under /softeng/<username>.

Any files added to hsl during the day will be incrementally added to softeng at the above times. Files deleted from hsl will not be deleted from softeng during the day. Any differences are reconciled every morning at 7.00am when any files present on softeng but not on hsl will be deleted.

You can copy files from /softeng/<username> to replace accidentally deleted files but remember they will only remain here until 7.00am the next morning when the systems are synchronised.

Important file systems on hsl are exported to softeng: such as /numerical and /home/mathsoft.

Updating software

If you need to update compilers or other applications software on the systems please be sure you know what you are doing - particularly on how it will effect licenses. If in doubt seek advice!

Final Comment

If you find any differences in using the two machines - please tell someone.