GETTING STARTED (COMMAND LINE)

1. Get Duo

DUO is required to access the majority of UM services and all HPC services. If you need to set up DUO please visit this page.

2. Get a Great Lakes user login

You must establish a user login on Great Lakes by filling out this form.

3. Get an SSH Client & Connect to Great Lakes

You must be on campus or on the VPN to connect to Great Lakes.  If you are trying to log in from off campus, or using an unauthenticated wireless network such as MGuest, you have a couple of options:

Mac or Linux:

Open Terminal and type:
ssh [email protected]
You will be required to enter your Kerberos level-1 password to log in. Please note that as you type your password, nothing you type will appear on the screen; this is completely normal. Press “Enter/Return” key once you are done typing your password.

When you’re connecting for the first time, it’s not uncommon to see a message like this one:

The authenticity of host 'greatlakes.arc-ts.umich.edu (141.211.192.39)' can't be established. RSA key fingerprint is 6f:8c:67:df:43:4f:e0:fc:80:5b:49:1a:eb:81:cc:54. Are you sure you want to continue connecting (yes/no)?

 

This is normal. By saying “yes” you’re accepting the public SSH key for the system. This key will be stored in a local known_hosts file on your system so you won’t be prompted in the future. The keys from Great Lakes will NOT change. So, for example, if you get a new computer and SSH to Great Lakes, you’ll be prompted to add the key again.

We encourage you to compare the fingerprint you’re presented with, when connecting for the first time, to one of the fingerprints below. The format of the fingerprint you’re presented could be dictated by the SSH client on your machine.

RSA 6f:8c:67:df:43:4f:e0:fc:80:5b:49:1a:eb:81:cc:54
ECDSA Dae1G3gu0mtro2Rm15U6l8aQg4bGFnDQJhmGH3k+fKs
ED25519 9ho43xHw/aVo4q5AalH0XsKlWLKFSGuuw9lt3tCIYEs

In the example message given above, we are presented with the RSA key fingerprint and its MD5 value, which is the same value as in the above table.

If you’re NOT seeing one of these fingerprints, submit a ticket to [email protected] and do NOT connect to the server via SSH until discussing with an ARC staff member to determine if there is a security issue.

To avoid being prompted to accept the key on a new system you may choose to pre-populate your SSH known_hosts file with the pub keys from Great Lakes. The keys can be found in the FAQ

 

Windows (using PuTTY):

Download and install PuTTY here.

Launch PuTTY and enter greatlakes.arc-ts.umich.edu as the host name, then click open.

If you receive a “PuTTY Security Alert” pop-up, this is completely normal, click the “Yes” option. This will tell PuTTY to trust the host the next time you want to connect to it. From there, a terminal window will open; you will be required to enter your UMICH uniqname and then your Kerberos level-1 password in order to log in. Please note that as you type your password, nothing you type will appear on the screen; this is completely normal. Press “Enter/Return” key once you are done typing your password.

All Operating Systems:

At the “Enter a passcode or select one of the following options:” prompt, type the number of your preferred choice for Duo authentication.

4. Get files

You can use SFTP (best for simple transfers of small files) or Globus (best for large files or a commonly used endpoint) to transfer data to your /home directory.

SFTP: Mac or Windows using FileZilla

  1. Open FileZilla and click the “Site Manager” button
  2. Create a New Site, which you can name “Great Lakes” or something similar
  3. Select the “SFTP (SSH File Transfer Protocol)” option
  4. In the Host field, type greatlakes-xfer.arc-ts.umich.edu
  5. Select “Interactive” for Logon Type
  6. In the User field, type your uniqname
  7. Click “Connect”
  8. Enter your Kerberos password
  9. Select your Duo method (1-3) and complete authentication
  10. Drag and drop files between the two systems
  11. Click “Disconnect” when finished

On Windows, you can also use WinSCP with similar settings, available alongside PuTTY here.

SFTP: Mac or Linux using Terminal

To copy a single file, type:

scp localfile [email protected]:./remotefile

To copy an entire directory, type:

scp -r localdir [email protected]:./remotedir

These commands can also be reversed in order to copy files from Great Lakes to your machine:

scp -r [email protected]:./remotedir localdir

You will need to authenticate via Duo to complete the file transfer.

Globus: Windows, Mac, or Linux

Globus is a reliable high performance parallel file transfer service provided by many HPC sites around the world. It enables easy transfer of files from one system to another, as long as they are Globus endpoints.

  • The Globus endpoint for Great Lakes is “umich#greatlakes”.

How to use Globus

Globus Online is a web front end to the Globus transfer service. Globus Online accounts are free and you can create an account with your University identity.

  • Set up your Globus account and learn how to transfer files using the Globus documentation.  Select “University of Michigan” from the dropdown box to get started.
  • Once you are ready to transfer files, enter “umich#greatlakes” as one of your endpoints.

Globus Connect Personal

Globus Online also allows for simple installation of a Globus endpoint for Windows, Mac, and Linux desktops and laptops.

  • Follow the Globus instructions to download the Globus Connect Personal installer and set up an endpoint on your desktop or laptop.

Batch File Copies

A non-standard use of Globus Online is that you can use it to copy files from one location to another on the same cluster. To do this use the same endpoint (umich#greatlakes as an example) for both the sending and receiving machines. Setup the transfer and Globus will make sure the rest happens. The service will email you when the copy is finished.

Command Line Globus

There are Command line tools for Globus that are intended for advanced users. If you wish to use these, contact HPC support.

5. Submit a job

This is a simple guide to get your jobs up and running. For more advanced Slurm features, see the Slurm User Guide for Great Lakes. If you are familiar with using the resource manager Torque, you may find the migrating from Torque to Slurm guide useful.

Batch Jobs

Most work will be queued to be run on Great Lakes and is described through a batch script. The sbatch command is used to submit a batch script to Slurm. To submit a batch script simply run the following from a shared file system; those include your home directory, /scratch, and any directory under /nfs that you can normally use in a job on Flux. Output will be sent to this working directory (jobName-jobID.log). Do not submit jobs from /tmp or any of its subdirectories.

$ sbatch myJob.sh

The batch job script is composed of three main components:

  • The interpreter used to execute the script
  • #SBATCH directives that convey submission options
  • The application(s) to execute along with its input arguments and options

Example:

#!/bin/bash # The interpreter used to execute the script #“#SBATCH” directives that convey submission options: #SBATCH --job-name=example_job #SBATCH --mail-type=BEGIN,END #SBATCH --nodes=1 #SBATCH --ntasks-per-node=1 #SBATCH --mem-per-cpu=1000m #SBATCH --time=10:00 #SBATCH --account=test #SBATCH --partition=standard # The application(s) to execute along with its input arguments and options: /bin/hostname sleep 60

How many nodes and processors you request will depend on the capability of your software and what it can do. There are four common scenarios: