Facilities > VLA > Documentation > Manuals > Computing Resources > User Accounts and Remote Access

User Accounts and Remote Access

by Gustaaf Van Moorsel last modified Sep 02, 2016 by Drew Medlin

Requesting an account

A valid entry in the my.nrao.edu User Database (UserDB) is required for account access.  Please ensure your email address therein is correct before requesting an account.

To request a computer account perform the following steps

  1. Ensure your default email address is correct at my.nrao.edu
  2. Submit a ticket at https://help.nrao.edu.
    1. To log in, use the same user ID and password as when accessing the Proposal Submission Tool or the Observation Preparation Tool.
    2. Under 'Select a department' choose "VLA/GBT/VLBA Archive and Data Retrieval" which will ensure the ticket is directed to the appropriate group.
    3. Indicate how long you will need the account, the default is one month: 2 weeks for processing plus 2 weeks grace period to transfer data products.

A unique UNIX based computer account will be created upon receipt of the request ticket.  The account name will be ‘nm-<#ID>’ where <#ID> is your numeric UserID in the UserDatabase, the account password will be the same as the one used above to submit the request.

You will receive an automated email delivered to the address registered in the UserDB when the account is created.  The email will include your account name, account expiration time and a pointer to this documentation.

The assigned account allows access to the NMASC ssh portal, authenticated ftp (sftp) server, the processing cluster master server and any assigned cluster nodes.  It does not grant access to other NMASC systems or staff machines.

Requesting Resources

Cluster node reservation requests must be issued on the cluster master node: nmpost-master.  This server is not directly accessible from outside the NRAO.  To access it from a system outside the NRAO you must first login to the ssh portal:  ssh <username>@ssh.aoc.nrao.edu from there you can ssh to nmpost-master: ssh nmpost-master.

To reserve a cluster node for interactive use run the command nodescheduler on nmpost-master.  The command takes two arguments, # of days to reserve the node and number of nodes.  Please limit number of nodes to 1 unless you can show a need for multiple servers.  For example:

nmpost-master% nodescheduler --request 14 1

would reserve one node for 14 days.  Running nodescheduler with no arguments will provide usage information.   Once a node has been assigned (could take anywhere from seconds to hours depending on demand) you will receive an email listing which node you were assigned and how to release the node when you are done.  Please release the node when you are done or won't be using it for an extended period of time (days).

Once a node has been reserved, your account and only your account has access to it.  For information on available software (e.g. CASA, AIPS, Miriad) see https://science.nrao.edu/facilities/vla/docs/manuals/computing-resources/software