NC State High Performance Computing
High Performance Computing

Remote Desktop Login News

This announcement is for three new capabilities:
  • LINUX DESKTOP ENVIRONMENT on the HPC
  • COMPLEX GRAPHICS AND VIDEO on the HPC
  • INTERACTIVE JOBS VIA THE LSF SCHEDULER on the VCL image
 
  • Linux Desktop Environment on the HPC
  •   Do you need any of the following:
      Desktop Environment on the HPC?
      To click and drag folders/files from your computer to the HPC file system?
      To click and drag folders/files from the Andrew File System (AFS) to the HPC file system?
      To run a web browser client on the HPC - to click and download files from web servers to the HPC?
      To run a web browser client to access the iRODS file system - to click to upload or download files between the iRODS file system and the HPC file system?
      Now this is possible with a Remote Desktop program to access the HPC login node in the VCL.
      To try it out: For users that have already used the HPC login node in the VCL (HPC-VCL), the instructions will only take a few minutes - please follow the instructions and try it out. For first time users of the HPC-VCL, they must first request access to that image: Send a request to oit_hpc@help.ncsu.edu with “access HPC-VCL login node” in the subject line.   When access is granted, go to vcl.ncsu.edu
    • Click on “Reservations”
    • Click the “New Reservation” button
    • Under the “Please select the environment you want to use from the list:” dropdown list, select “HPC (CentOS 7.2 64 bit VM)”
      • Tip: If you type “hpc” followed by a space in the dropdown box, the list will be filtered to only show the HPC environment
    • Select how long you would like to reserve the environment next to the “Duration” dropdown box
    • Click “Create Reservation”
    • The reservation is usually ready in less than 5 minutes, you will see a “Connect” button when it’s ready, and an email will notify you as soon as it is ready.
    • Click “Connect” and follow the instructions you see
      Clicking the “Connect” button will yield a pop-up window, showing two options for logging in.
    • Connect to reservation using SSH
      • You are probably already familiar with this option.  Use an SSH client such as the ssh command on Linux or the PuTTy application on Windows to interact with the remote VCL computer in a text-based terminal.
    • Connect to reservation using xRDP for Linux  NEW!
      • This is the new, graphical connection option.  Near the bottom of the Connect dialog box, click "Get RDP file" to download a file that contains the connection information for your current reservation.
      • On most systems, you can simply execute the downloaded .rdp file and it will automatically launch your computer’s remote desktop program and connect to the remote VCL computer. If there are issues with blank GUIs, the "color depth" in the VCL user preferences needs to be changed to 24. Specifically, when you are on the Reservations page of vcl.ncsu.edu, in the top horizontal menu, go to Manage > User Preferences > RDP Preferences (on the LHS menu) > Color Depth: 24
      • The above process has been validated for Windows machines. On Mac and Linux machines, there may be some small additional steps needed: On Mac and Linux machines, using the Remote Desktop App with username and password should work. For Linux, you may want to use xfreerdp.
        • Mac machines: If Remote Desktop didn’t come with your Mac OS X you can download the free Microsoft Remote Desktop app from the App Store. There are 2 versions in the store - the older 8.0 and the newer 10.0 versions (at time of writing this document). The older 8.0 version works better (more explanation of this further down). In the Remote Desktop app, (a) go to Preferences > Security tab and select “Always connect, even if authentication fails”, (b) set the Color Depth to 24. If using the newer 10.0 Remote Desktop version, the fields in the login panel may appear blank, and the text in them invisible. This can still be used - simply pretend that the first 2 fields are correctly filled out (the Session and username fields), and fill in the password field. This should work.
        • Linux machines: If Remote Desktop didn’t come with your OS you can download xfreerdp. When connecting to the HPC-VCL, the initial login panel may fail to log you in, even though you provided the correct username and password. If this happens, in the log-in panel, change the 1st field (Sessions) to the alternative (there are two options, Xvnc and Xorg).
      • Once logged into the remote VCL computer, the screen may appear black for about 35 seconds. Then you will see a Linux desktop environment:
      • A command-line terminal can be opened with Applications > Terminal
      • The user’s HPC home directory can be browsed by clicking on the Home icon
      • HPC file systems such as gpfs_share as well as AFS file space including the user’s AFS home directory can be browsed by:
        • Click on the Home icon
        • Clicking on “Other Locations” at the bottom of the left column
        • Opening “Computer” in the main pane:
      • Files from the local computer the user is connecting from may be accessed on the remote VCL computer by clicking on the thinclient_drives icon on the desktop:

        This will open a window containing folders that correspond to the drives on the user’s local computer.  In the example below, the C: folder corresponds to the C: drive on the Windows computer used to connect via Remote Desktop: (Note: Performance may be slow when browsing or copying files via thinclient_drives.  For larger file transfers, the user will be better off using an SCP or SFTP client.)
      • Do you need to use the iRODS data grid file system? The HPC-VCL is also an iRODS client, and the iRODS file system can be accessed by it: https://datascience.oit.ncsu.edu/faq/#q1
    Once you have an initialized iRODS account, you can start a Firefox web browser client on the HPC-VCL, then go to   irods-cloudbrowser.hpc.ncsu.edu  

  • Complex Graphics and Video on the HPC
  •     Do you need to visualize complex graphics, or view movies on the HPC? Or to interactively use software in GUI mode, like Matlab, Fluent and VMD? This can now be done. Now it is possible to use a Remote Desktop program to access the HPC login node in the VCL.  

    With this capability, graphics performance is just like sitting at the login machine, rather than having graphics data traveling slowly through an X11 (eg. PuTTy) tunnel to the user’s machine. This means that using the Matlab GUI (for example) will be smooth and responsive, instead of clunky, even from off campus.  

    To try it, logon to the HPC-VCL using the Remote Desktop instructions above, and open a command line terminal (also described above).
    module load matlab2017b
    matlab

    Or
    module load vmd.-1.9.1
    vmd  

  • Interactive Jobs via the LSF Scheduler on the VCL image
  •     Do you need to debug a job-submission-batch-script line by line? Or to login to the compute nodes that the scheduler reserved for you? Interactive jobs via the LSF scheduler are now possible on the HPC-VCL image (this capability has always been there on the standard HPC login nodes).  

    For example, do an interactive version of the R example given in the HPC R documentation: https://projects.ncsu.edu/hpc/SoftwarecdA/UsingR.php? Login the HPC-VCL, and open a command-line terminal as described above. Create a z.r file, with the lines:  

    pdf ("xh.pdf") #set graphical output file hist(rnorm(100)) #generate 100 N(0,1) variates and plot their histogram dev.off()  #close the file  

    Then make the interactive reservation, and start a tcsh shell:
    bsub -Is -n 12 -W 10 -R "hc span[ptile=12]" tcsh
    >>Job <453268> is submitted to default queue ,<debug>.
    >><<Waiting for dispatch …>>

    After the reservation has been made, run the batch-script line by line:
    source /usr/local/apps/R/R-312.csh
    R CMD BATCH --vanilla  z.r

    To log out of the compute node and exit the interactive session:
    exit

    To view the results:
    display xh.pdf

    Another example: To log on to the .|NVIDIA P100 gpu node (and start a tcsh shell): bsub -Is -q gpu -R "select[ngpus>0] rusage[ngpus_shared=2]" -m n3h39 tcsh
    >>Job <443595> is submitted to queue .
    >>Waiting for dispatch ...
    >>Starting on n3h39

    Then run the following diagnostics:
    nvidia-smi  

    Have fun!

    Last modified: June 02 2018 11:59:58.