Frequenlty Asked Question about the Hoffman2 Cluster

Questions in this FAQ:

  1. Which Password do I use to login?
  2. My program writes lot of scratch files in my home directory. This results in exceeding my disk space quota. What is the solution?
  3. How do I transfer my files from the Hoffman2 Cluster to my machine
  4. The ATS consultant sent me an email about lot of left over jobs running under my loginid. How do I delete them?

Questions and Answers

Which password do I use to login?

As a user of an ATS-Hosted Cluster, you will have the following passwords:

  • For each cluster you can access you will have a separate login id and password.
  • You will have a single username and password that you can use to login to both the UCLA Grid Portal and the UC Grid Portal.

Your cluster login ids and passwords are independent of each other and of your grid portal username/password. For example, when you change your password on one of the ATS-Hosted Clusters, it changes on that cluster and that cluster only. Your passwords on the clusters can be, and probably are, different. There is only one grid portal password which is used by both the UCLA Grid Portal and the UC Grid Portal. If you request that the password you use for one of the grid portals be changed, you will have to use your new password when you login to either grid portal.

In addition to these passwords, everyone affiliated with UCLA has a UCLA Logon ID and Password. You are sometime asked to authenticate with your UCLA Logon ID and Password when requesting services via the web, even from ATS web sites. The UCLA Logon ID and Password is independent from any login id/password or username/password combinations that ATS has issued to you.

My program writes lot of scratch files in my home directory. This results in exceeding my disk space quota. What is the solution?

There are several things you can do:

  • If you are a member of a research group which has contributed nodes to the Hoffman2 Cluster, your PI can purchase additional disk space for use by the members of your group.
  • Each process in your parallel program can write to the local /work on the node it is running on. When the program finishes, you can copy the files off to a place where you have more space. Since /work is local to the nodes, using it is very efficient.
  • You can write to /u/scratch and you have 7 days after the job completes to copy the files somewhere else.

How do I transfer my files from the Hoffman Cluster to my machine?

If the size of an individual file does not exceed 100 MB, you can download it to your local machine, or transfer it to another cluster that you can access at UCLA from the UCLA Grid Portal.

For any size file, you can use the scp command to transfer a file or directory from one machine or system to another. For saftey reasons, as outlined in the Security Policy for ATS-Hosted Clusters, always scp from your machine to the ATS-Hosted cluster. NEVER scp from the ATS-Hosted cluster back to your local machine.

An ATS consultant sent me an email about lot of left over jobs running under my userid. How do I delete them?

You can get the processor id's using the ps command and filter them using the grep command to select only the jobs you want to delete and feed the result to kill command.

ps -u loginid | grep myjob | awk '{print $1}' | xargs
ps -u loginid | grep myjob | awk '{print $1}' | xargs kill

Replace loginid with you loginid and myjob with the executable name.