CLASSE Group Information

CLASSE groups should be used when multiple people need access to a common file, directory, or filesystem. For a list of all groups, including who is a member of what group, please see WikiGroups. To create a new group or modify the members of a group, please submit a ServiceRequest.

Most of our filesystems are accessed from unix systems using NFS. Please see NfsDirs for a list of available NFS filesystems. Some of our unix filesystems are also available to Windows and Mac OS X using Samba.

Common tasks

The following examples can be used as references for many common filesystem permission tasks.

How do I find the linux or macos path for \\samba\vacuum?

1. Browse to https://www.classe.cornell.edu/private/computing/filesystems.html
2. Search that page for your desired filesystem

How do I make /nfs/acc/vacuum/Manuals writable by anyone in the vacuum group?

If you find you are unable to execute the following commands for a directory, submit a ServiceRequest to the computer group.

1. Make sure everything in Manuals (that was created before the sticky bit was set) is in the vacuum group. Please note that this must be done by the owner of the file or directory you are changing.
   • chgrp -R vacuum /nfs/acc/vacuum/Manuals
2. Make sure everything in /nfs/acc/vacuum/Manuals is set so that the group permissions are the same as the user permissions.
   • chmod -R g=u /nfs/acc/vacuum/Manuals
3. Set the sticky bit on /nfs/acc/vacuum/Manuals. This makes it so that any new files or directoies in /nfs/acc/vacuum/Manuals are in the vacuum group instead of each user's default group.
   • chmod g+s /nfs/acc/vacuum/Manuals
4. Make sure everyone who works in /nfs/acc/vacuum/Manuals first executes umask 002. We recommend this is done in the appropriate login scripts. umask 002 makes it so that any new file or directory you create are readable and writable by everyone in the relevant group.

How do I change my primary group to cesr?

In general, this is not needed. However, this can be accomplished for your current session by executing newgrp cesr.

Who is in the "cesr" group?

1. See WikiGroups .

What groups are dab66 in?

1. See WikiGroups .
2. or from a command line, execute groups dab66

What groups are dab66 in, and what are the group IDs for those groups?

1. id dab66

Who has drafting as a secondary group, and what is the drafting group ID (gid)?

The following two commands will each show you that the drafting gid is 119.

1. getent group drafting

Whose primary group is drafting?

Once you know the gid of the group you are interested in, you can find out who uses that as their primary group.

1. getent passwd |grep ":119:"

Managing group membership (for group admins)

Please see CLASSEGroupManagement .