A Configurable UPS Monitoring Daemon

Powstatd is a configurable UPS monitoring daemon designed to work with SysVinit. Powstatd was originally developed under RedHat Linux 5.2, with more recent versions (post 1.4) developed with Debian/Woody. It should work on any SysVinit-based Unix system, including, apparently, Sun/Solaris and SGI/Irix (see enclosed porting instructions).

Powstatd monitors a serial connection from a "dumb" or "relay" UPS for power failures and shuts the machine down gracefully if the power remains off for more than a prespecified interval.

Powstatd can also be configured to allow a master machine to control, via a network connection, several slave machines connected to the same UPS. This allows you to run several machines off the same UPS, with only one of the machines actually reading the UPS status over the serial line. When compiled with security option enabled, powstatd will timestamp and encrypt all master/slave communication to protect slave machines from malicious shutdowns.


Powstatd was developed by Alberto Maria Segre and is copyrighted by The University of Iowa. It is distributed under the terms of the GNU General Public License.

Current Version of Powstatd

The current release of powstatd is version 1.5.1 (April 27, 2001).

This release of powstatd, when optionally configured to use the secure communication protocol, is based on TEA, the Tiny Encryption Algorithm, developed by David Wheeler and Roger Needham at the Cambridge University Computer Laboratory.

TEA uses a 128-bit key, and is therefore considered ``strong cryptography,'' which is classified as ``munitions'' by the US government (the irony here is that TEA was developed in the UK, and its source code can be freely imported into the US; once in the US, however, it cannot then be reexported).

The US government's restrictions on the export of munitions does contain an exemption for material which is freely available in public libraries, but it is unclear whether anonymous ftp sites and web pages actually qualify as ``public libraries.''

I cannot, therefore, make the complete version of powstatd available directly on this US-based website.


Download and unpack the appropriate tar archive and type "make doc" to produce a postscript copy of the man pages, which contains complete installation and configuration instructions.

Last modified: Wed Apr 10 2002
The University of Iowa / Castor Laboratories / alberto-segre@uiowa.edu