Friday, March 27, 2015

Sending large files to people

In a previous post we described the Globus file transfer service.  It is designed to transfer single or multiple large data sets between two sites.  Here we show an alternate approach using the Filesender service offered by Internet2 that is focused on file transfers of any size between individual’s desktop or laptop computers. It is a particularly convenient way to overcome email attachment file size limitations.

The process is real easy, just follow these simple steps:

  1. Point your web-browser at:
  2. Login using "University of Michigan" as your Organization.
    1. Then use your UMich Uniqname and Kerberos password
  3. Fill in all the information fields of the form, especially the email address.
  4. Upload your files.
  5. Then click on the "Send" button. The recipient will be sent an email with a link and instructions on downloading the files. When the download is complete you will receive an email telling you so.

Does someone need to send you large files but is not from an Internet2 member Institution?  No problem!  After you log into the filesender site select "Guest Voucher" at the top of the page.  You can then have an email sent to the other person with a link allowing them to send a file or multiple files back to you or anyone else. Be advised though that this is a one time use for each voucher.

As always, the HPC support staff on campus are available to help, simply send an email to

Tuesday, March 17, 2015

Intel Xeon Phi's Available on Flux

ARC-TS now has available as a technology preview, 8 Intel Xeon Phi (Wikipedia) 5110p cards.  These are known as MIC's or Many Integrated Core.  These are an accelerator card that fits into a slot on a Flux compute node and a code can offload portions or all of the work to the card.

As a technology preview, there is no additional cost for using the Phi's.  All that is required is an active Flux allocation and users can test the Phi's. The only other requirement is all Phi jobs must be less than 24 hours long.

The Phi cards support three modes of operation, Automatic Offload, Compiler Assisted Offload, and Native.  The first two are well tested, the last works but is not as well tested.  All intel-comp compiler and mkl math library modules on Flux support the Phi.

You can request a phi with PBS with:

qsub -I -l nodes=1:mics=2  -q flux -A account_flux -l qos=flux -V

This will provide two Phi's and one CPU. Flux currently has one node with 8 Phi cards.

PBS will do set two variables:

PBS_MICFILE   -> list of hostnames of assigned phi's  good for native mode.
OFFLOAD_DEVICES  -> csv list of devices for controlling auto offload (MKL) or compiler assisted offload.

$HOME is mounted on the card, as is all the software but /scratch currently is not,  it should sometime in the future.  This should only affect users running Native Phi code.

For software the Phi requires some environment changes to work.  We created a module called xeon-mic.  When loaded it will set some sane defaults but will print what it set.  Users are encouraged to experiment with many of the settings available.

module load xeon-mic

In future posts we will show examples using the Phi.