Login Nodes and transfer hosts

By February 24, 2016

Login nodes

The login nodes are the front end to the cluster. They are accessible from the Ann Arbor, Dearborn, and Flint campus IP addresses and from the UM VPN network only and require a valid user account and a Duo two-factor authentication account to log in. Login nodes are a shared resource and, as such, it is expected that users do not monopolize them.

Login nodes for flux

The Flux login nodes are accessible via the following hostnames.

  • flux-login.arc-ts.umich.edu
    will connect you to the general Flux login hosts
  • flux-campus-login.arc-ts.umich.edu
    will connect you to the login hosts that can run software that requires you be on campus.
Policies governing the login nodes

Appropriate uses for the login nodes:

  • Transferring small files to and from the cluster
  • Ordinary data management tasks, such as moving files, creating directories, etc.
  • Creating, modifying, and compiling code and submission scripts
  • Submitting and monitoring the status of jobs
  • Testing executables to ensure they will run on the cluster and its infrastructure. You should limit your use of Flux login nodes to programs using 4 processors or fewer, less than 16 GB of memory, and that do not run longer than 5 minutes. Larger or longer processes may cause problems for other users of the login nodes. We reserve the right to terminate processes if we think they are causing or may cause a problem. If your program needs more extensive resources, you should use a PBS interactive job

Any other uses of the login nodes may result in the termination of the process in violation. Any production processes (including post processing) should be submitted through the batch system to the cluster. If interactive use is required then you should submit an interactive job to the cluster.

Transfer hosts

The transfer hosts are available for users to transfer data to and from Flux. Connections are limited to SCP and SFTP and interactive logins are not allowed. Currently the transfer hosts have 10 Gbps connections to the network, which is much faster than connections to the login nodes. Connections to the transfer hosts are allowed from the same networks as are the login nodes.

Transfer hosts for flux
  • flux-xfer.arc-ts.umich.edu

Supported sftp and scp clients