In order to manage the 1000+ Unix/Linux hosts in SCS, we install a custom managed-computing environment on hosts that we deploy. This environment provides distributed system management capabilities, integration with SCS services, and better security. This computing environment is known as "Dragon", after the dragon in the logo of the School of Computer Science. Modifications and additions that have been made to the stock vendor environment on Unix/Linux hosts running SCS Dragon include:
- OS and vendor-provided software updates are pulled from a local mirror of the distribution vendor's package repository. This mirror lives on the SCS network to provide reliability and conserve bandwidth.
- Hosts are configured to run the vendor's automatic software upgrade system nightly.
- An additional software repository is configured which contains locally-modified or patched versions of vendor-provided software, in order to provide timely response to security problems or bug fixes. These updates are provided in the vendor's package format, and are integrated into the standard OS package management systems.
- Configuration is installed that grants Facilities staff access to the host for system maintenance and troubleshooting.
- Many system configuration files get the majority of their defaults from the OS vendor, but Facilities provides a few tweaks that are merged into the existing system configuration. The automated configuration-merging systems also take care to preserve any user or local administrator changes away from the vendor or Facilities defaults.
- The vendor's AFS client is installed as the standard means for providing central file services.
- Kerberos support is enabled for many services by default.
- The mail system has been configured to forward all mail to the central SCS mail system.
- A daemon is installed to provide desktop backups (on machines that request them)
- SUP & Depot are installed to provide nightly updates of locally-written software (mostly system administration utilities used by Facilities for automated management of a large number of systems)
For the most part, host-specific customizations can be done according to the OS vendor's typical mechanisms. See the SCS Dragon Unix/Linux administrators guide for information on how to perform certain system administration tasks and customize Dragon hosts in situations that deviate from the vendor's provided utilities. The SCS Dragon Unix/Linux quick reference has an overview of some common questions when using SCS Dragon on Unix/Linux hosts.