Linux at BU -- Frequently Asked Questions

Common Issues

Help! I can't receive mail on my system!
How do I access Matlab, Mathematica, Maple, or Splus?
Which version of BU Linux am I running?
How do I set up Baseline Reporting on my Linux workstation?
Help! I finished the install, and I can't log in.
Help! I did an upgrade, and I can't log in even as root!
I installed BU Linux, and now my dual-boot Windows XP won't work!

1. Help! I can't receive mail on my system!

As the saying goes: that's a feature, not a bug. For security reasons, we've configured sendmail (the program responsible for transferring e-mail between servers) to be inaccessible from other computers. This is great for most workstations, but obviously isn't want you want for a mail server.

If you want to receive mail from the Internet on your BU Linux 3.0 or 4.0 machine, you have to make some modifications to your configuration.

First, make sure incoming mail traffic is allowed through your firewall. You can do this with the GUI firewall configuration tool. Type sudo system-config-securitylevel (or "lokkit" in BU Linux 3.0) to launch this program. Note that this is "write only" — it doesn't read in your previous configuration, so be sure to re-enable any other incoming services you wish to allow.

Then, configure your MTA to listen on the network interface.

For postfix:

Change to the directory /etc/postfix
Edit the file main.cf, and find the line that reads:
inet_interfaces = localhost
Change this to be:
inet_interfaces = all
Save the file, and reload the configuration with sudo service postfix reload
Test by typing telnet hostname.bu.edu 25. Typing "quit" will exit out of the test.

For sendmail:

Change to the directory /etc/mail

Edit the file sendmail.mc, and add dnl to the start of the line that reads:
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')
This will comment out the option that restricts sendmail access to localhost only.
Save the file, and type sudo make
Add the line sendmail: ALL to the file /etc/hosts.allow
Reload the configuration with sudo service sendmail reload
Test by typing telnet hostname.bu.edu 25. Typing "quit" will exit out of the test.

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2. How do I access Matlab, Mathematica, Maple, or Splus under BU Linux?

We provide access to various proprietary programs via AFS. If you have BU Linux release 3.0 (Doolittle) release, everything is already configured. Just type matlab in a terminal window, and the application will start. For BU Linux 4.0 (Bossanova), the AFS client is still experimental. In the meantime, install our "fake-afs" package: sudo apt-get install fake-afs usrlocalITbin. This will create an automount entry that will provide access to the /afs data via NFS.

Please be aware that access to these programs is restricted according to a the license agreements with the various vendors.

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3. Which version of BU Linux am I running?

Type: cat /etc/bulinux-release

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4. How do I set up Baseline Reporting on my Workstation?

(Updated answer coming soon.)

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5. Help! I finished the install, and I can't log in.

BU Linux machines can authenticate to the main campus Kerberos servers, but need to have a local database of account information. In some departments, this is provided via LDAP or NIS, but in most cases, you'll need to set up this yourself.

This is actually easier than it sounds. All you need to do is log in with the root account with the password you created during the installation process. If you are in graphical mode, this should take you immediately to the GUI user account management tool, with which you should find it very easy to add a BU login account which uses your central Kerberos password. If you're in text mode, simply type useradd -K username to accomplish the same thing. You can also create a local-only (non-Kerberized) account with a local password.

No matter which course you chose, you may also want to add your account to the wheel group, which will give you administrator (root-equivalent) access via sudo and with the various graphical configuration tools.

When you've created your account, exit the GUI tool or log out of the root account, and log back in as yourself.

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6. Help! I did an upgrade, and I can't log in even as root!

We've seen this problem with upgrades to Bossanova several times. Luckily, it's not too hard to fix. You need to boot into single user mode to fix the problem:

reboot the system
at the GRUB bootloader prompt press 'p' to enter the bootloader password and unlock GRUB's administrative options. This password will be intially set to whatever you chose as your root password in the installer.
press 'a' to append a keyword to the kernel boot line.
type the keyword single, and press the enter key.
the system will boot, and ask for the root password, and then put you at a command prompt in single-user mode.

Once in single user mode, simply run system-config-authentication, and say 'next' on each screen. (Pressing F12 twice should accomplish this.) This will rewrite your authentication configuration files to what should be correct.

Then, simply reboot with the reboot command.

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I installed BU Linux, and now my dual-boot Windows XP won't work!

This is a known problem with the Fedora Core 2 distribution on which BU Linux 4.0 (Bossanova) is based. Luckily, it can be easily corrected by following these steps. Note that this article also has information on preventing the problem from occuring in the first place.