Category Archives: English

Stuff written in English

CD/DVD drives in Windows 7 and code 39 error

A collegue’s desktop computer has twice lost touch with its DVD drive. The drive is OK, it’s recognized by the BIOS, it even booted from a FreeBSD DVD when told to do so. Yet Windows 7 refused to display the drive. The Device Manager utility complained about a missing driver service and something about a code 39 error. A surfing expedition revealed this article which gives some pretty accurate suggestions. Continue reading CD/DVD drives in Windows 7 and code 39 error

New server and first attempt at running FreeBSD/amd64 with ZFS for all storage

The switch to new hardware finally happened. This is the first server to run FreeBSD/amd64 under my supervision. ZFS is used for all storage on this server. I chose to install the newly released FreeBSD/amd64 9.0-RELEASE, before upgrading to FreeBSD/amd64 9.0-STABLE by source. It’s just a matter of preference, given my 13-14 years of experience with FreeBSD. Continue reading New server and first attempt at running FreeBSD/amd64 with ZFS for all storage

Up and running again late in December 2011

Sorry for the nearly two week absence. This web server’s 10 year old hard drive developed too many faults between December 9th and 10th, and the system became rather useless. The wonky hard drive was replaced with a brand new one this week. Nothing important got lost thanks to AMANDA and a fair number of backup tapes. Eventually the server will be restored to its former glory.

However, a new and fast server is in the works, possibly with a mirrored ZFS root pool on 2 drives and a ZFS raidz1 data pool on 3 drives. I doubt I can make the switch before sometime in early or mid January 2012.

I wish you all a merry Christmas and a happy New Year.

By the way, those of you who are geared towards computer science might want to watch Don Knuth‘s 17th Annual Christmas Tree Lecture entitled “Bayesian Trees and BDDs“.

One year of blogging, more or less

It’s been one year since I started this blog. I have accumulated 33 posts, including this one, and a handful of (experimental) pages.

It took a while before I felt brave enough to let Google index my blog.

As for comments, a few comments have been to the point, whereas the majority of comments has simply been spam. Why do spammers bother at all?

Only time will tell what the year 2012 has in store for me (to write about anyway).

Unless I decide to write another post during December 2011, let me use this opportunity to wish you, my gentle reader, a merry Christmas and a happy New Year.

Trond.

ZFS root fs on FreeBSD 9.0

Gone are the old MFS root fs image and the sysinstall utility. To create a useable ZFS root fs from the 9.0-RELEASE DVD we must specify an alternate location for the temporary zpool.cache file and an alternate mountpoint for the ZFS root fs by using a command like:

zpool create -o cachefile=/tmp/zpool.cache -m /tmp/zroot zroot /dev/gpt/disk0

Also, the FreeBSD distribution is now stored as a handful of xz compressed tar files in /usr/freebsd-dist on the DVD. Everything else remain largely the same. The instructions below also apply to 9.1-RELEASE.

See http://wiki.freebsd.org/RootOnZFS/GPTZFSBoot and http://www.aisecure.net/2011/05/01/root-on-zfs-freebsd-current/ for further details.

Keep on reading if you want my recipe for creating a ZFS root fs. Continue reading ZFS root fs on FreeBSD 9.0

Dialog boxes for file handling missing in AutoCAD?

A student came by my office today and wondered if I knew how to bring back the usual dialog boxes for file handling in AutoCAD. A quick search using Google revealed the filedia command.

The solution is to execute the filedia command, enter 1 (the digit one) as the requested input, hit the enter key, and voilà, normal dialog boxes appear whenever the new, open, and saveas commands are executed.

FreeBSD 9.0 as IPv6-only

At work we have native IPv6 connectivity along with IPv4. We’ve had IPv6 for nearly 5 years and IPv4 for the past 17 years.

On 2011-08-16, I grabbed an IPv6-only snapshot of FreeBSD/i386 9.0-BETA1 dated 20110727 and started experimenting with internet life using only IPv6. This particular machine is a virtual machine running inside VirtualBox 4.1.2 on my Windows 7 desktop at work. Continue reading FreeBSD 9.0 as IPv6-only