Category Archives: Systems Administration

Email files directly from the Linux console

It’s not a great habit to get into, but sometimes it can be very quick and convenient to email a file to yourself directly from a bash SSH console. Note: Because this uses email, this method isn’t secure. Think carefully about the contents of what you’re sending before you email files directly from your system. [...]
Also posted in Debian, General, Linux | Leave a comment

Debian APT repos not found? Switch to the archive!

If you’re running an older release of Debian and you’re seeing messages like this when you try and apt-get installs, then it’s probably because your release has been taken off the main mirrors and can no longer be updated that way. W: Failed to fetch http://ftp.uk.debian.org/debian/dists/lenny/main/binary-amd64/Packages 404 Not Found [IP: 83.142.228.128 80] W: Failed to [...]
Also posted in Debian, Linux | 4 Comments

Tuning JVM Memory Settings

Update: Andrew Wang’s blog post (http://www.umbrant.com/blog/2012/twitter_jvm_tuning.html) is a pretty nice quick guide, well worth reading in conjunction with this page. Sorting out sensible JVM memory settings in a production environment can be a tricky business. There are some great articles, blogs and lengthy white-papers out there explaining the details of how the JVM manages memory, [...]
Also posted in Java | Tagged , , , | Leave a comment

A more sensible PowerShell prompt

The default PowerShell prompt is long and irritating. I switch my default to the following: In order to achieve this, I have the following script: function prompt { Write-Host("%") -nonewline -foregroundcolor Yellow; return " "; } c: cd Scripts " "; You’ll also note that I change the default working directory to C:\Scripts, which is [...]
Posted in Systems Administration | Tagged , , | Leave a comment

Use nmap to locate ProCurve switches on your network

Nmap is a great tool; utterly indispensable for network administrators. If you haven’t got it yet goto http://nmap.org or install via your favourite package manager. Here’s one of my frequently used nmap commands – very simple, but gives you a quick list of IP addresses for all of the ProCurve switches on your network. nmap [...]
Posted in Systems Administration | Tagged , , , , | Leave a comment

Automated batch reboot of HP ProCurve switches via telnet

Today I had occasion to reboot about 20 ProCurve 3500yl switches, thanks to yet another firmware bug. The simplest way of doing this is with the “reload” command issued via telnet. Rather than logging into each switch and issuing the reload command by hand I threw together an Expect script which automatically logs into the [...]
Posted in Systems Administration | Tagged , | 3 Comments