Articles in the System Administration category

  1. OpenSSH: Using a Bastion Host

    Posted on in System Administration

    Quick and dirty OpenSSH configlet here. If you have a set of hosts or devices that require you to first jump through a bastion host, the following will allow you to run a single ssh command:

    Host *
        ProxyCommand ssh -A <bastion_host> nc %h %p
    

    Change the Host * line to best …

  2. Cache has broken packages, exiting

    Posted on in System Administration

    I've been getting the following error from cron.daily in my inbox lately:

    /etc/cron.daily/apt:
    Cache has broken packages, exiting
    

    That's an annoying email to get everyday. I decided I would apt-get clean and that would probably fix the problem:

    $ sudo apt-get clean
    $ sudo apt-get dist-upgrade
    Reading package …
  3. Removing a Single Line from known_hosts With sed

    Posted on in System Administration

    Ever so often, something changes on the network, and you find that your .ssh/known_hosts file has gotten out of date. Usually this happens after an upgrade or device change. You'll get the rather ominous warning that REMOTE HOST IDENTIFICATION HAS CHANGED!

    If you are confident that someone isn't doing …

  4. Bypass RBL Check in Exim

    Posted on in System Administration

    Although I do not use Exim myself, I have clients that do. Recently, we noticed that it was taking more than 20 seconds for their SMTP banner to display when initiating checks from the monitoring server. Connecting to the server locally (on any interface IP address) did not suffer the …

  5. Enable gzip in Nginx

    Posted on in System Administration

    If you have ever used any tool to optimize a web page, you know that compressing the return traffic to the client is a big win. In nginx, this is done with the gzip module. The easiest thing to do is add gzip on; to the http stanza in your …

  6. Magento Home Page Returns 404 Status Code

    Posted on in System Administration

    Naturally, I ran into this problem in the middle of the night when the client was asleep and I had no access to the Magento administrative interface. The short story is that after running a re-index of the site, the home page began returning a 404 error status. A bit …

  7. [MacPorts] upgrade gnutls failed

    Posted on in System Administration

    MacPorts logo

    I ran into this issue while trying to install wine-devel on my Mid 2012 MacBook Pro running El Capitan and MacPorts 2.3.4. As the install progressed, here is the error I got:

    Error: org.macports.build for port glib2 returned: command execution failed
    Please see the log file …

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