Install and run ColEm

ColEm is an emulator for the old but impressive ColecoVision. This article will show you how to install the emulator and a short introduction how to use the emulator. I build the sources successully on my notebook (running Slackware64-14.1) and on my Cubietruck (running Linaro-13.04).

7z

If you're faced with a 7z file then you need a program like 7za to extract these archives. If your distribution has no 7z package you need to download the sources first:

SSD TRIM

Since I have my new SSD (SanDisk SDSSDHP128G) I read a little about performance tuning for SSD's etc. One thing I read was to activate trim (if possible) and to deactivate noatime during mounting. I have only one SSD where I store my entire operating system on so the partition layout is fairly simple:

importvg failed

The situation so far: a customer has two systems with a couple of luns presented to them. Two luns (hdisk2 and hdisk7) were imported as testvg on Node 2. Exporting the VG on Node 2 worked fine, importing on Node 1 failed (unfortuanatly I've no error message here). First I checked the physical volumes (note that I only take a closer look at hdisk2 and hdisk7 which belongs to the VG testvg):

unrar

When you need to extract a RAR archive then you need unrar. Depending on your distribution you need to install unrar first. I use Slackware so I have to download the source and compile them. The first step is to download the sources:

Database crashed, controlfiles deleted and missing archive logs

Current situation: tonight a database crashed and the controlfiles have been destroyed/deleted. When I tried to open the database then I got:

$ export ORACLE_SID=KARDB
$ sqlplus "sys/password as sysdba"
SQL*Plus: Release 11.2.0.3.0 Production on Tue Apr 22 18:03:00 2014
Copyright (c) 1982, 2011, Oracle.  All rights reserved.
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size                  2232840 bytes
Variable Size             524291576 bytes
Database Buffers          536870912 bytes
Redo Buffers                5541888 bytes
ORA-00205: error in identifying control file, check alert log for more info

IP forward and masquerading

Today I was in the challenge to setup a router. We ware at a meeting with a small wireless router connected to the internet and a couple of hardware with copper interfaces only. We didn't had physical access to the wireless router. We just saw the ESSID to connect to. Luckily I had my notebook running Slackware with a wireless and a copper NIC. The situation was like:

Editing MP3/ID3 tags

A couple of days ago someone asked me how to change the ID3 tag in MP3 files via commandline. There are a couple of programs out there and the first one I found did the job right: id3ed
To get id3ed running download the source from http://freecode.com/projects/id3ed first. Then extract the tar file and build the source:

Setting up a tftp server with Slackware

Setting up a tftp server with Slackware is an extremely easy task. Unlike most
of my articles there is no need of compiling any additional software since
everything is shipped with Slackware. So let's get started.
The first thing you need to do is to edit the inetd.conf file and comment out
the line that's starts with tftp:

Destroy a deported disk group

Today I wanted to destroy a disk group that was deported. A import fails because there were missing disks (it was just a test environment so loss of data was wanted):

# vxdg import testdg
VxVM vxdg ERROR V-5-1-10978 Disk group testdg: import failed:
Disk for disk group not found