Lab Mac Triage Documentation

The Mac Labs are lab rooms throughout the MC building dedicated to giving students access to Mac computers. In any of these labs, students can enter their WatIAM credentials and log into one of the computers in their own environment.

System Specifications

• Locations: MC 2062, MC 2063, MC 3003, MC 3004, MC 3005, and MC 3027
• See Mac Lab Closures for closure dates Is this page still relevant? It looks really old and outdated.

Hardware

Some things I can think of that might be appropriate in this section include the type of macs that are being used

Some examples:

• Machine's name: markus002.student.cs.uwaterloo.ca
  • May be moved to another server in the winter term
• Server's name:
  • Server1
  • Server2

Software

• User logins
  • Authentication requires Student Active Directory (cs-teaching) credentials
  • Cannot support one user logging into a machine multiple times. The lab Macs use network home directories. The login / logout hooks provide some temporary links to the local disk to improve performance, and then remove them at logout. Any machine already logged on will be in an unstable state after you log out of another machine.
  • People with access:
    • anyone with an active account in the CS Student Active Directory Domain (CS-TEACHING) should be able to login to a lab Mac
    • any Math and specifically any CS student, or Instructor, or Tutor, or student in a CS course has access; any ISG or CSCF staff has access
    • there are NO group restrictions

Some other things I might be appropriate in this section that are not yet here. One thing that comes to mind is the OS of the macs, and other similar information.

Authentication and Authorization Information

Many systems demand authentication before they can be accessed. List the information required to gain access to the system. Please do not put passwords on this page. This page will be public and accessible by Google.

People

• Administrator: Yan Martel
• Point of contact (expert): Edward Chrzanowski
• Stakeholders:
  • I created these two stakeholders below by just brainstorming some things that I imagine the mac labs to be used for. The elipses are there to show that more information might want to be added for them but you can add or remove stakeholders as you see fit, of course.
  • CS Students
    • Uses the mac labs for assignments where they don't have the required software
    • ...
  • Course Tutors
    • Use mac labs to hold office hours
    • ...

Terminology

For example:

• Definitum
  • In a definition the word being defined is the definitum
  • Is a fancy word that nobody ever really uses
• MarkUs
  • A marking system in which students can submit their code and faculty can provide feedback and assign grades
  • Originates from the University of Toronto

Guides to the Completion of Scheduled Tasks

Some tasks must be completed on a regular basis. List the scheduled tasks from least frequently recurring to most frequently recurring. Each one must have a detailed guide on how to go about completing the task and how often/when the task must be completed. Try to be as detailed as possible.

Are there any scheduled tasks for this system? Anything to do with maintenance? One thing that comes to mind is that we might need to check for software updates once and awhile.

Guides to the Completion of Common Requests

This section outlines the guides to completing tasks that are commonly requested by clients

Recover files from backups

If clients lose their files, they may ask for them to be recovered from the system's backups. Information about the backups and how this can be done are at Backup Macs.

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Double sided printing is not enabled by default. But it can be enabled on a per-machine/per-student basis; ie, the student would have to set it up on each different machine they want to use.

   System Preferences
   Print & Fax
   click the printer in the list
   click Options & Supplies
   click Driver
   "tick" Duplex Unit
   click OK 

Then select Double Sided in the particular application you want to print from

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Formatting should be similar to the guides to the completion of scheduled tasks section

Level-3 heading with a very high-level description of the request

1. Description of step
   • Details and notes about how to complete the step
   • Details and notes about how to complete the step
2. ...

Check for Success

How to see if the requested task was completed successfully

For example:

Set Up an Exam

1. Log into the system for setting up exams
   • located at insert_url
   • use your WatIAM credentials
2. ...

Check for Success

A list of students and where they will be seated for their exam is outputted

Common Failures/Bugs & Troubleshooting

Replace this text with a symptom that somebody would use to describe what happens when he/she logs into more than one machine

The lab Macs use network home directories. The login / logout hooks provide some temporary links to the local disk to improve performance, and then remove them at logout. Any machine already logged on will be in an unstable state after you log out of another machine.

Fix

All that needs to be done is that the user must log out of both machines. Do you have anything to add here?

A user cannot log in

If a single user is not able to log in, there is a possibility that the user is simply not entering the correct credentials. Remember that authentication requires Student Active Directory (cs-teaching) credentials.

Fix

1. First, verify with users that they are:
   • using only the first 8 characters of their usernames
   • Entering their passwords correctly:
     • if they set their passwords in 2011 via https://www.student.cs.uwaterloo.ca/password/ they should enter their entire passwords
     • if they set their passwords before 2011, only the first 8 characters should be entered, even if their passwords are longer. Passwords should only use the "aA1" character set - no funnies.

1. Get the student to log in to the Mac in the Consultant's office. There are no group restriction and all that is required is a valid account and password in the Active Directory
   • if login fails, then a password change is probably required (see the Passwords are rejected section)

• • it is now very unlikely that other rejections will happen because a user is not in a group that has lab access;
  • if no-one can log in:
    • suspect that the time is incorrect (AD and Kerberos allow only small differences in time between client and server); a reboot may fix it; otherwise, sometimes they "lose" the configuration and a local administrator login is required to change the System Preference, Date and Time, to "automatic" from ntp.student.cs.uwaterloo.ca
    • we have had a couple of instances where the Domain information cached on the Mac becomes corrupt; preventing user login; and preventing administrator ability to bind/unbind the machine to the Active Directory - see ST#70642 for local administrator actions to repair
  • Login / operation may be very slow if the student fileserver is heavily loaded
  • Several times student accounts have been accidentally orphaned - the symptom is that they can authenticate, but then not "do" anything, effectively they do not have permissions on their home directory after it is mounted. Support people have to un-orphan them, and make sure it doesn't happen again - could have been caused by bad Registrar data for example.
  • If students have trouble logging in for a lab exam, we have had cases where it is their first attempt of the term. If they didn't attend the first lab and re-set their password, a process about a month later will re-set the password, effectively disabling the account until they go through a password re-set with the Consultants

Passwords are rejected

What does it mean for a password to get rejected?

Fix

Passwords that are being rejected must be reset This can be done in one of two ways:

1. Have the user log into https://www.student.cs.uwaterloo.ca/password/ with his/her WatIAM password
2. Reset it with passwd on a student CPU host, such as cpu02.student.cs Will this be enough information for people acting on your behalf to figure out what needs to be done? If it is, just lever it. Otherwise try to add some more information.

X11 Problem

Poeple with this error experience the following error message:

/software/ssh-openssh-4.3krb/private/xauth: error in locking authority file /u5/iturner/.Xauthority
Terminal type is xterm
cpu02:~> xterm
X11 connection rejected because of wrong authentication.
X connection to cpu02.student.cs:10.0 broken (explicit kill or server shutdown)

The cause is the existence of a file in the home directory [What's the name of this file?], created by the X11 program on Leopard (Mac OSX 10.5.x). The existence of this directory will also cause X11 to not work properly on the older, Mac OSX 10.4 machines (none currently) [The "none currently" is a bit ambiguous in it's message. Does it mean that there are no macs running OSX 10.4 in the Mac labs?]

Fix

This appears to have been solved with our Spring 2011 Snow Leopard image. However, should the error occur anyway, do the following:

1. Press "ctrl-c" to exit the error condition
2. Exit all existing host sessions
3. In either a local xterm or the local Terminal, enter rm .Xauthority-c

Check for Success

You should be able to start host sessions, eg xterm on cpu18 from the X11 "Applications" on the Menu bar, and, they should behave properly, even allowing "child" X sessions, as you would expect.

Printing Problems

The paper size default for a new student account might show up as A4; once they select US Letter, it should "stick" (note: the A4 paper size will probably make the printer "hang" waiting for the correct paper to be loaded) Is this a problem that needs to be triaged? I'm not sure exactly.

Trouble printing from a lab mac and gets an email back from lpquota saying the job was rejected because of a missing quota on imacxxx.local

Our lab macs get that .local name if they have seen a network problem, especially while booting. One can observe the situation by starting a Terminal window, and typing hostname. The proper response is imacxxx.student.cs etc, the improper one is imacxxx.local.

Steps to fix

Simply unplugging and re-plugging the network cable from the mac will solve the issue. The user can also try rebooting.

Machine will not boot and the power light is flashing

The pattern with which the power light is blinking gives information about the cause of the issue.

Blink pattern	Issue
A flash once every second	Either there is bad RAM or no RAM present
Three flashes, a pause, and then three more flashes (occurs continuously)	There is only a marginal amount of RAM

Steps to Fix the Issue

Either the RAM modules are bad or they are not seated properly. All you need to do is open the ejector clips and install the ram modules. This is done by pushing very hard with both thumbs, closing the ejectors, and then replacing the cover. If this does not fix the issue, install one module at a time or reinstall the original ram that came with the iMac.

Apple also provides some more general information on fixing this issue

Machine will not boot but beeping occurs

As Ed researched in ST#66267 I can't see information in this ST item. Not even a summary. Will people who are trying to fix this issue be able to gain information from this ST item? If not, we should delete this line

For New World Macs (1999 onward) and Intel-based Macs, the beep pattern provide information about the cause of the issue according to the following table:

Beep Pattern	Issue
1 beep	no RAM installed
2 beeps	incompatible RAM types
3 beeps	no good banks
4 beeps	no good boot images in the boot ROM (and/or bad sys config block)
5 beeps	processor is not usable

Steps to Fix the Issue

No fix information was provided in the source. Can you please add it?

Current Discussions Related to the System

Some systems have important long-term changes that are being discussed. If needed, a summary of each discussion may be included here.

See Also

Related ST Items

• https://cs.uwaterloo.ca/cscf/internal/request_beta/UpdateRequest?66267

Related Twiki Pages

• Trouble Shooting Lab Macs

Related EDocs

For example:

• EDoc 1
• EDoc 2
• ...

Related External Links

• http://www.cs.uwaterloo.ca/cscf/student/maclabs2006

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Extra notes from Drew for Edward to Review

• What do you want to do with the source Twiki page? (https://cs.uwaterloo.ca/twiki/view/CF/TroubleShootingLabMacs). It's basically the same content and it wouldn't be clean to have duplicate information

• This following section was included in the source. I don't really understand what it is trying to say. As a result, I don't know what do do with it.

Symptoms Which are NOT Problems

• "No Xauth data; using fake authentication data for X11 forwarding .....creating new authority" This is an artefact of the magic Jason invented for allowing single-signon from the lab Macs to student.cs cpu servers in the X11 program

I'm struggling a bit with this section. I can't figure out whether it is all talking about one big problem or whether there are many different problems (each with a different fix that will be needed). If it is many problems, each one will probably need it's own how-to.

Operational Problems

• First verify that the student has diskquota available; the Macs use network based profiles/home directories, and will exhibit strange behaviour if they cannot create working files; eg Firefox will refuse to start.
• Funny application behaviour in general can be observed when the fileserver is overloaded; eg, saving a Microsoft Office file will give a bogus permissions error, when the real underlying problem is a timeout communicating with the server. A possible workaround is to save the file temporarily in /tmp/username - that folder is local to the system, but will be deleted when you log out, so make sure to copy the file to your home directory space.
• Microsoft Excel error "Can't record macro" - log out and back in; the login hook deletes some Microsoft Office preference files that can become corrupted, then running Excel re-creates them.
• Occasionally other programs will get corrupted preference files (suspected because of concurrent logons sometimes). They can be removed, since they will be dynamically re-created in a default state. They are in the USER, not System, space ~/Library/Preferences and typically have a form like com.optima.PageSpinner.plist; some applications may have multiple plists. There may also be removable files in ~/Library/Application Support/ specific to the problem application