Cluster-Specific Tools

Finding information with "gather"

The "gather" command, which is available only on the blue.unix cluster, allows you to find information such as which machine in the cluster you last logged into, what processes you have running on any of the machines, and where any "abandoned" edit session temporary files may be.

Below is a table of options which gather supports and explanations for each.

Option Explanation
lastlogin Last time you logged in and on which node
editsessions Locates active or abandoned edit sessions
by looking for temp files from vi, jove, emacs, and pico
uptime Runs the "uptime" command for each node
tempfiles Locates any files you may own in /tmp area of each node
friends Runs the "who" command for locating other users on any node
processes Runs "ps" command to show processes you own

 

Locating /tmp files Some Unix applications, such as editors, create temporary files in the area "/tmp". Each machine in the Unix cluster (node1.unix, node2.unix, etc.) has a local /tmp area. Locating your temporary files can be a problem with this configuration. If your session is suddenly terminated, such as from an unexpected modem disconnection, when logging back into "blue.unix.virginia.edu", most likely you will not end up on the previous cluster node. If you can't remember which node you were disconnected from, "gather tempfiles" will query each node in the cluster for any /tmp files you own. Then you can log into the specific node (e.g. node2.unix.virginia.edu) where your /tmp files reside to recover them. Lastlogin information On non-cluster Unix machines, you can find out your most recent login date and time by using the "lastlogin" command. However, each time you log into the cluster, you may not be on the same node (node1.unix, node2.unix, etc.). The "gather lastlogin" command allows you to get the last times you logged into any of the cluster nodes. The gather command is available from the Unix command line and from within Umenu.

Unsubscribing from a mailing list with "fmail"

When subscribing to a mailing list, the list processor retains the name of the machine from which any given email arrives. In order to unsubscribe from that list, the request must come from that user on that specific machine. When machine names are "retired", such as fermi.clas and darwin.clas, people who subscribed to lists while on those machines have trouble unsubscribing. ITC has written a "mailing list tool" for those who are migrating to the blue.unix cluster and need to send unsubscribe requests to mailing lists requiring the mail to come from "faraday.clas.virginia.edu" or any other retired machine name.

To use this mailing list tool, type the command: 

	fmail

at the Unix prompt. If you use Umenu, fmail is available as an option in the "Cluster Commands" menu.

Since fmail behaves the same when run from the command line and from within Umenu, instructions for using fmail can be found in the Umenu Reference Manual.

Retrieving deleted files with "snapshot"

One of the advantages of having your home directory on the NetApp server is the ability to retrieve recently deleted files without having to go to a backup tape. For more information about how the NetApp creates and maintains these "snapshots", see the document "Retrieving Deleted Files"

To use this tool, type the command: 

        snapshot

at the Unix prompt. If you use Umenu, snapshot is available as an option in the "Cluster Commands" menu.

Since snapshot behaves the same when run from the command line and from within Umenu, instructions for using snapshot can be found in the Umenu Reference Manual.

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