PNCE-Unix Groupspace Structure

PNCE-Unix Environment Documentation

Overview of Groupspace Directory Structure

The PNCE-Unix environment maintains a distinction between homespace and groupspace. Files related to an user's research activities are expected to be stored on disk space provided by the research group. A standard directory structure is provided for this group space to facilitate support and ease of use.

The standard mount point for this disk space is: /group/GNAME where GNAME is the abbreviation for the research group. This disk space is automatically backed up by OIT and uses the Andrew File System (AFS) for storage. Because AFS uses ACLs instead of standard Unix file permission bits, it is strongly recommended that groups keep to the standard directory structure provided, which has been designed to allow for flexibility, security, and consistency. If you have files which require greater privacy than the standard directory structure gives, it is recommended that you contact PCS to ensure that the required level of privacy is met (you can set it yourself, but setting AFS ACLs can be tricky if you are not familiar with them, and once your private files are available to the world, it may be difficult to take them back).

Underneath the main group directory /group/GNAME are the following subdirectories:

• common: A shared working area in which all group members have read-write access. This is intended to facilitate sharing of files among a group.
• software: A directory for group specific software and binaries. By default this is readable by all PNCE-Unix/Glue users. It normally consists of different AFS volumes (which look like directories but are somewhat different) for each software package. The designated computer contact person can request new volumes for new software packages, and/or install software here. Because PNCE-Unix/Glue is a heterogeneous cluster, we strongly suggest groups adhere to our binary directory structure.
• project/PROJECTNAME The designated computer contact for the group can have PCS create AFS volumes for various projects. These are intended for multi-person projects, and to facilitate the organization and cooperative tasks required by such projects. Permissions will be set up on a case by case basis
• pub/public_html This is the location for the group to put their various official, departmental web pages. NOTE: Any pages located in this directory are accessible from the main departmental web page (via the URL http://www.physics.umd.edu/rgroups/GROUP and, upon request, http://www.physics.umd.edu/GROUP), and therefore reflect upon the image of the Physics Department, the College of Computer, Mathematical, and Physical Sciences, and the University. Research groups are expected to take care to uphold a suitable image with these pages. Unofficial and personal web pages must be placed in the user's home space and served off the www2.physics.umd.edu server. By default, all members of the group have read-write access to this area, and of course it is world readable. Contact PCS if you wish more restrictive access controls
• pub/test_html If you are planning major remodelling of your web pages, you can request a test site viewable via the http://testwww.physics.umd.edu web server. This enables you to try things out without breaking your production pages.
• user/USERNAME Upon request from the designated computer manager from the group, members of the research group can receive a quota'ed workspace volume in the group's groupspace. These are AFS volumes, and so must be created by PCS upon request from group managers. The user has full read-write access to the directory, and other group members by default have read access. Contact PCS if you have need for more restrictive access. Requests for additional quota should be made through the designated computer contact person.

Users may wish to create links from their home directory into various directories in their group space. This may reduce the amount of typing required to change to the desired directories. E.g., one may wish to issue the commands:

Users should also note that all files residing in a research group's disk space are considered property of the research group. Access to those files may be denied, or the files may be read and/or deleted by designated computer contact persons at the behest of the principle investigator of the group. Personal and/or private files should be placed on the users home space.