FAQ

1. Who is eligible for an account on the facility?

All Swinburne staff and students are eligible for accounts as are researchers in the field of astronomy and space sciences based at publicly funded institutions within Australia. International collaborators may also apply for accounts but cannot be the lead on a research project.

2. How do I access the facility?

All access is through the head node g2.hpc.swin.edu.au and from there you can submit jobs to the queue or login to one of the interactive nodes. You should not login directly to any other nodes unless otherwise advised.
See more details on Access green II page.

3. What operating system is used?

All nodes are running CentOS 6.

4. How do I differentiate between gSTAR and swinSTAR nodes?

All gSTAR nodes are denoted gstarXXX and all swinSTAR nodes as sstarXXX, where XXX is a 3-digit node number.

5. How do I change my login password?

6. How can I change my login shell?

You can change your login shell, just type:

/home/changeShell

in your terminal. This information will take a few minutes to propagate, and you will have to login again for it to take effect.

7. How can I avoid session timeouts?

There are a few ways to do this but a simple method is to go to the .ssh directory on your host machine and create a file called “config”. In that file place the line

ServerAliveInterval 120

and that should do it, although on some machines you may need to also run the command

chmod 600 ~/.ssh/*

to ensure the file has the correct permissions.

8. How can I find out more about using GPUs?

If you would like to learn more about using graphics programming units (GPUs) in your research a good starting point is the NVIDIA Developer Zone or our HPC/GPU webinar series.

You can also look through slides on Getting Started with the CUDA programming language for GPUs, an introduction to the OpenACC directives for accelerating code with GPUs and the Thrust acceleration library.
These were all presented at a recent CUDA Easy workshop at Swinburne (thanks to Michael Wang, Paul Mignone, Amr Hassan and Luke Hodkinson).

Another great starting point is to go to the GPU Technology Conference website and search through past presentations using their On-Demand tool. You can search by field and/or topic, for example, and most likely someone in your field has already tackled what you are hoping to do.

9. Why I’m getting “Disk quota exceeded” message?

As a gSTAR/SwinSTAR user, you may be a member of more than one group. In order to list these groups, you can use the command

groups

Each group has its own storage quota, which is shared between its members. If you want to get the quota information of a specific group on lustre, you can use

lfs quota -g  /lustre

.

The problem for some users recently has been that the files or directories created under a project directory (e.g /lustre/projects/) have not been created with the correct group ownership because of either they inherit wrong group ownership, or they have incorrect group association. The following commands might help you to fix this issue:

  • To find the files and the folders owned by a specific group, you can use

    find  ­group 
    
  • In order to map the contents of a certain folder to a specific group you can use

    chgrp -R  /path/to/folder

    This will change the group ownership of all files and folders (including sub-folder) within a particular directory.

  • In order to ensure that new files and folders are created with your project group ownership, you can use

    find . /path/to/folder -type d -exec chmod g+s ‘{}’ \;
    

    This will set a special permission so that new files are created with the assigned group owner of that folder. The path used for ‘path/to/folder’ would typically be your working directory.

You will probably face the disk quota exceeded issue because one or more of your directories are associated to the general group “cas”. In order to find all the files and the directories associated to “cas” in a specific path and change them to your group you can use

find /path/to/folder -group cas -exec chgrp  ‘{}’ \;

Also, Users should be aware that just because a folder is owned by the correct group does not mean that files created under that folder will be. An example of this would be:

  • drwxrwxr-x 1 joe p001_swin 4096 Jul 10 12:00 temp_folder

versus:

  • drwxrwsr-x 1 joe p001_swin 4096 Jul 10 12:00 temp_folder

Only in the second example, new files and folders will be created under the ownership of the “p001_swin” group. The important permission here is the group stickybit. This is set easily with

chmod g+s /path/to/folder

Any user with write access will be allowed to change this bit.

The other thing that you should be aware of is the use of rsync. A very typical rsync command method is to simply use the ‘-av’ options. This is a preset for archive, which includes a particular flag for permission preservation. What happens with this is that new writes or syncs of existing files will carry the permission bits of the source files and directories, which may overwrite the existing permission where we have already set the stickybit for inheritance on lustre or on nfs cluster. If you are writing data into some of these directories via rsync, you should ensure your source files also have at least the stickybit applied before transferring, or you could rsync without the “-p” option in your command to inherit the destination.