VASC | Resources | System administration

Contents

Computer accounts - How do you apply for them?
Passwords - What passwords do you need to set? How do you set them?
Disk space and quotas - Where are your files? How do you access them from Windows?
VASC directory structure - How are the files organized?
Reporting problems - Who do you contact when your computer stops working?

Computer accounts

VASC members have up to four different computer accounts at CMU, which can be rather confusing to newcomers. Here's a breakdown of the different accounts, their purpose, and how to apply for them. To simplify things, it is recommended that you use the same username for your SCS Unix and Windows accounts. For information on setting up your new accounts, see the VASC resource advisor.

Passwords

If you are not confused by the four computer accounts, you won't have any trouble with remembering up to six different passwords that you may need. Many of these passwords arise from the fact that SCS uses Kerberos for authentication, and different passwords give access to specific network services such as mail and ftp (details). Here's a breakdown of what each password is used for and how to change it.

Disk space and quotas

VASC members typically have three sources of file storage space: a relatively small amount of SCS-administered disk space (a.k.a. AFS space) for their home directory; a much larger amount of personal or project disk space located on their desktop machine or project machines; and additional disk space located on the VASC file servers. Also, Windows machines have the normal Windows-formatted disk space on their local drives. Files in all of these places can be set up for access from any VASC machine, whether it is Unix or Windows. For details on cross-platform file access, see the VASC resource advisor.

SCS account disk space

Your SCS account is stored on AFS (the Andrew file system). You should definitely read about afs permissions, which behave differently than on other Unix file systems.

Accessing disk space - You are automatically given AFS disk space when your SCS account is set up. This is your default UNIX home directory.

• Unix - Accessible under /afs/cs/user/{username}
• Windows - Accessible with the Transarc AFS client (installed by default).

Quotas - Use the "fs listquota" command to check your quota. Use jeeves to increase your quota.

Permissions - Permissions are managed through afs access control lists (ACLs). Use the "fs sa" command to set permissions, "fs la" to list permissions.

Backups - Nightly backups are performed by SCS facilities (details). If you accidentally delete a file, you can retrieve yesterday's version from the OldFiles directory linked off your home directory. Contact help@cs for other restore requests.

VASC workstation and project disk space

In addition to your afs disk space, there is local space on your personal machine as well as on machines associated with your lab or project. Use the "df" command to list the disk partitions. These local partitions can be shared with other VASC workstations at the request of the owner. Send your request by e-mail to ius-bugs@cs.

Accessing disk space

• Unix - Accessible from any VASC workstation under /IUS/{hostname}_{diskname} for workstation disk partitions or /IUS/projects/{projectname} for project space. For example, use /IUS/gibson_usr0 to access the /usr0 partition on gibson.
• Windows - Accessible from \\vasc\hosts for workstation disk partitions or \\vasc\projects for project disks.

Quotas - Use the "df" command to determine how much space is available on a partition.

Permissions - Files and folders use Unix-style permissions. Change them with the "chown" "chgrp" and "chmod" commands.

Backups - Backups are performed on a per-machine basis by SCS facilities (details). Use the "lastbackup" command to check the backup status, or look at the file /etc/dumpdates. Contact help@cs for restore requests.

Additional VASC disk space

If you run out of disk space in afs and on your personal machine and project machines, then you can request an additional 2GB of disk space from ius-bugs@cs.

Accessing disk space

• UNIX - Accessible from any VASC workstation under /IUS/users/{username}
• Windows - Accessible under \\vasc\users\{username}

Quotas - Use the "df" command to determine how much space is available on a partition.

Permissions - Files and folders use Unix-style permissions. Change them with the "chown" "chgrp" and "chmod" commands.

Backups - Backups are performed on a per-machine basis. Use the "lastbackup" command to check the backup status, or look at the file /etc/dumpdates. Contact ius-bugs@cs for restore requests.

 

VASC directory structure

This is a summary of the locations of VASC-administered disk space. Additional information is given in the disk space and quotas section.

Unix

NFS automounts are used for disk sharing on Unix machines. The automount program will mount the directory only when it is requested. The directory will not appear to be there until you try to access it.

• /IUS/{hostname}_{diskname} - shared Unix workstation disks
• /IUS/users - user disk space
• /IUS/projects - project disk space

Windows

Unix network disks are accessed from Windows via a samba server.

• \\vasc\hosts - shared Unix workstation disks
• \\vasc\users - user disk space
• \\vasc\projects - project disk space

Reporting problems