mit sailing

Various projects with the MIT sailing program. Bluewater boats Aleida, Nevermore, and X-Dimension. Hobie 16, 18, and 20 catamarans.


These are my notes about setting up Nagios to monitor a few machines. Previously I was using smokeping and some hand-rolled perl scripts. After 10 years of power supplies going bad (usually due to heat), hard drives failing (usually due to heat), and UPSs bursting into flame (who knows?), I decided to get serious and monitor more information so I could catch things before they got bad.

simple backup

This is a simple backup script based on rsync and hard links. I use it to do on- and off-site, automated, rolling, incremental backups of both servers and workstations. All that is required on the client is sshd, rsync, and the backup user's public certificate. It will tunnel using ssh if necessary. The package includes crontab, logrotate, and logwatch parts as well. The resulting snapshots can be shared via NFS or SMB for end-user access, if necessary.

throttle ssh

Throttle incoming ssh connections if they happen too often. This is an iptables-based approach to block brute-force attempts to guess passwords or otherwise attempt to break in via a publicly-accessible ssh daemon.

reverse tunnel

Establish an ssh tunnel from a remote system to an always-on server. Then connect back to the remote system by logging in to the server then ssh to the tunnel. This method of reverse tunnel is handy for connecting to remote systems that are behind a firewall or NAT, have an address that changes, or whose internet connection can only be established by the remote system.

power monitoring

Notes from the installation of a couple of Energy Inc TED (The Energy Detective) and Brultech ECM (Energy Consumption Monitor) power monitoring systems. The TED hardware works well, but the software is poor. The Brultech hardware works even better, but the software is windows-only. Luckily there are open source solutions for both systems.

weather monitoring

Notes from the installation of a WS2080 (manufactured by Fine Offset and distributed by Ambient Weather) weather monitoring system. Notes about wview software customization for the Davis Vantage Pro system at the MIT sailing pavilion. The Ambient Weather hardware is cheap - 4 ambient weather systems cost as much as a single Davis system - but it does work. There are a few open source solutions for monitoring the hardware.