Categories
Tracks

Tracks

I like this one:

Categories
Tracks

Tracks

This time, I only provided the initial crossing and the switches branching out, the rest was done by Clemens.

Categories
Life

Heavy lifting

Carrying both kids used to be easy. No more. 17 + 21 kg is heavy lifting.

Categories
Tracks

Tracks

Clemens is a bit sick today, so I’m staying home with him and we built this set of tracks together:

Categories
System Administration

Moving …

The disks in my old root server are finally both failing, so I’m moving all my stuff to a new machine.

As usual in IT, you get a lot more power for the same money now, and so I’m quite pleased with the performance of the new server. I’ve tried to do a more secure and cleaner setup this time and distribute the service over domUs in a XEN setup. We’ll see how that works out in real life.

One thing is different this time: I can’t take my old, free /29 with me to the new server. Additional IP-addresses cost extra money now, and I’m not prepared to pay extra for them. Instead, I’ve got a block of IPv6 addresses and will run anything that I can’t DNAT/proxy via v6.

I moved email service over two weeks ago, yesterday evening this blog. If something is not working as expected, tell me.

Categories
System Administration

Linux, iostat and device names

My favorite tools for looking at the I/O load of Linux boxes are iotop and iostat. Running “iostat -xm 5” is one of the first things I do whenever I have the feeling that a server might be I/O-bound. The output is perfectly fine and useful on your typical one-disk box, but once you throw in either Xen or DM-Crypt, then the output is not so intuitive any more as it is no longer clear what each of the dm-XX devices is actually holding.

So I whipped up the following quick perl script to translate them:

#!/usr/bin/perl -w
#
# Replace dm-x names in stdin with names from /dev/mapper, e.g.
# iostat -xm 5 | $0
#
# Otmar Lendl, 2012/08/24
#

use strict;

my %m;

foreach my $l (split(/\n/, `ls -l /dev/mapper`)) {
# lrwxrwxrwx 1 root root      8 May  3 18:49 vg1-abusehelper--swap -> ../dm-21
        if ($l =~ /\d\d:\d\d ([\w-]+) -> \.\.\/(dm-\d+)/) {
                $m{$2} = $1;
        }
}

while(<>) {
        s/(dm-\d+)( *) /substr($m{$1}. (' ' x 80),0,length($1.$2)).' '/eg;
        print;
}

The quotes in substitution line should be plain single quotes, not the typographic nonsense that wordpress insists on inserting.

Share and Enjoy!

Categories
Internet Life Uncategorized

Link Dump

Once again, I have collected too many tabs in my browser session. This blog-post will collect them:

Categories
Pet Peeves

Dear Niki/AirBerlin

For this week’s flight from Paris CDG to Vienna I used the Web-Checkin. This is the boarding-pass I got from them:

All nice and fine, but one important detail is missing: Which terminal?

Categories
CERT Internet

The Evolution of Conference Wireless

  • 2003: RIPE offers to rent out PCMCIA wifi cards to attendees of the RIPE conference.
  • 2007: Every attendee has a laptop with built-in wifi.
  • 2012: Every attendant brings a Laptop and at least one smartphone, some bring tablets as well.

We have ~500 attendees at #FIRSTCON this week; I wonder how many distinct clients the wifi net has seen.

Categories
Internet

IPv6 Usage

Ever since I enabled IPv6 for /dev/otmar, the logs show that

  • I’m not getting that much traffic anyway.
  • Hardly any of it is via IPv6.

My Cacti shows:

(blue is v4, and green is v6)

This widget from IPv6-test.com shows whether your connection is v6 enabled — and show statistics over all visitors here.