Group Services in the Brave New World

Welcome to the ACM group hosting infrastructure. This document assumes you are already familiar with its sibling, Navigating the ACM’s Services (sometimes also called README-BRAVE-NEW-WORLD).

The ACM offers JHU campus groups storage, web hosting, database hosting, mailing lists, and other services as needed.


You should feel free to delete this document from your group directory when you feel sufficiently comfortable with the contents. It can always be found at /afs/

AFS Groups

We will have created two AFS groups for your use:


The former can manage the latter (i.e. can add or remove users) and can also manage itself (isn’t that swell), so that as your membership and officers change you won’t ever have to send us email or anything! :)

To add a user to your group, run


And to remove a user, say


And similarly for -admins.

Note that your users (or even admins!) do not have to have ACM accounts; you can use their JHED IDs just as well, by using $ for the $USER_NAME_HERE part. (Though you will have to ask them to authenticate to the ACM systems at least once before our systems “believe” they exist; see Using JHED Identities with the ACM Systems in Navigating the ACM’s Services.)

Creating Additional PTS Groups for Your Group

Feel free to create additional groups as your access control needs dictate. We suggest that new groups be owned by your -admins group. The magical incantation to use is

pts creategroup -name org:$YOUR_GROUP_NAME_HERE-$NEW_GROUP_NAME -owner org:$YOUR_GROUP_NAME_HERE-admins

To be a little more concrete about it, here is an example:

pts creategroup -name org:foo-officers -owner org:foo-admins


Each group has

  • A 40G home volume
  • A 1T private “scratch” volume

The home volume, as with users’ home volumes, will be guarded with extreme care, regularly backed up, and archived for disaster recovery. The scratch volume less so, though of course we will try not to lose the data if we can.

Your group volume is mounted at /afs/, with “scratch” mounted as a folder therein. “OldFiles” and “OldFiles.scratch” are, as usual, read-only snapshots of your volumes as of last night.

As far as default permissions go, everyone in org:$YOUR_GROUP_NAME_HERE has rlidwk permissions on /afs/, meaning they have full access rights but cannot change the permissions for your group volumes.

The -admins group has rlidwka permissions, meaning they can set the access lists for your group. For more about this, refer to Navigating the ACM’s Services. Should one of your administrators be exceedingly silly and mess up the ACLs in such a way that your group can no longer access or administer your group volume, contact the ACM admins and we’ll fix it for you.

Mailing List(s)

We also offer mailing lists for group use. These are fully decoupled from AFS and so may be used independently – that is, you don’t have to have storage space with us to have a list, and vice versa.

List administration and archives may be accessed via the web at