How do I ask a question?

Press "edit" near the top of the page and ask your question at the bottom like this one.

What documentation exists for new users?


How do I create a new user?

sudo adduser USERNAME

sudo adduser USERNAME sshusers  # give user the ability to login through ssh

sudo setfacl -m user:www-data:x ~USERNAME # Let www-data get into the user's directory so it can read public_html

How do I login, my password isn't working!?

You must use ssh keys if you are in the admin group (have sudo access).

Can you tell me a bit about how permissions are setup?

What services are running on the server?

Apache, ssh, and a moinmoin wiki instance.

How do I update the server?

To update ubuntu: sudo aptitude update && sudo aptitude full-upgrade and reboot if a new kernel gets installed.

How do I update drupal and its modules?

To update drupal and drupal modules, use drush.

Where are things located?

DOMAIN/~user corresponds to a user's public_html under his or her home directory.

The drupal install is in /var/www/drupal. There are some static files in there which eventually should cease to exist (old site).

There are also two directories for seminars /var/www/{GASC,bhmn}. To add a new directory similar to GASC or bhmn you should add it at the same level and edit /var/www/drupal/.htaccess to include a rewrite condition like RewriteCond %{REQUEST_URI} !^/gasc(/.*)$ [NC] (this is so spelling correction works on this part of the site). Permissions are setup using ACLs (query gasc or bhmn with getfacl for an example).

What happened during the Great Server Crash of 2011 and how was it resolved?

The server did not actually "crash" in the sense that a program error halted the system. Here is what happened. Before winter break 2011-2012, updates were run that installed a new kernel. However, /boot is on its own partition about 200mb in size and was full because older kernels were never removed. During the new kernel's installation an error was reported that /boot was full and the kernel could not be configured but it was not noticed by the administrator installing the updates. When the server lost power over the break, it rebooted and tried to boot the new kernel which failed because it was not configured.

To resolve the issue physical access was required. An older kernel was selected from the grub prompt, a few old kernels were removed to free up space in /boot, the newest kernel was installed and configured, and then the system was rebooted.

In the future, policy should be set on how many old kernels should be kept around and apt-get output should be paid more careful attention to. It's suggested that when installing new kernels, the system be rebooted to verify the new kernel boots without issues. When deciding to install a new kernel, physical access should be easily obtainable.

NUWiki: WebServerAdminFAQ (last edited 2013-06-19 17:27:19 by 129)