This post appeared originally in our sysadvent series and has been moved here following the discontinuation of the sysadvent microsite
Ever wanted to record a log of an interactive console session? Easy, just use
the script utility. It’s probably already present on your system, no
installation required.
To start recording, run script --timing=script.tim script.log. This spawns a
new shell, recording stops when you exit from it.
To replay the log, run scriptreplay script.tim script.log. It is also
possible to speed up or slow down the playback speed. For example, in order to
play back the recording at half of the original speed, use scriptreplay
script.tim script.log 0.5. Ctrl+S pauses the playback, Ctrl+Q resumes.
The nice thing about script is that it records everything that happens on the
console, it’s not just a simple log of invoked commands. If you open a text
editor like vi in the recorded session, you’ll be able to see exactly how and
where you navigate the cursor, exactly how and when text was changed -
including any typos that were later corrected, and so on.
For the full documentation, check out the manual pages script(1) and scriptreplay(1).
Alarms made right
At my work, we’re very much dependent on alarms. The systems need to be operational 24/7. When unexpected issues arise, timely manual intervention may be essential. We need good monitoring systems to catch whatever is wrong and good alarm systems to make someone aware that something urgently needs attention. I would claim that we’re quite good at setting up, tuning, and handling alarms.
When I’m not at work, I’m often sailing, often single-handedly for longer distances. Alarms are important for ... [continue reading]