Working for a small non-profit, everyone has to wear lots of hats, and one that I have to wear from time to time (since no one else here can) is “sysadmin”. One of the perennial rules of system administration is: you can never give users enough bandwidth. The problem is, they eventually learn how fast your connection to the outside is, and then complain any time a download doesn't run at that speed. Of course, if you have a T1 or better, it's usually the other side that's the problem. So, I look to use our extra bandwidth during off hours to cache large pools of data that are often downloaded. With a organization full of Ubuntu machines, the Ubuntu repositories are an important target for caching.
Reading
Suppose you have a domain name, example.org, that has a primary MX host (mail.example.org) that does most of the delivery. However, one of the users, who works at example.com, actually gets delivery of <user@example.org> at work (from the primary MX for example.com, mail.example.com). Of course, a simple .forward or /etc/aliases entry would work, but this would pointlessly push email back and forth between the two mail servers — in some cases, up to three pointless passes before the final destination! That's particularly an issue in today's SPAM-laden world. Here's how to solve this waste of bandwidth using Postfix.
This tutorial here assumes you have a some reasonable background knowledge of Postfix MTA administration. If you don't, this might go a bit fast for you.
I thought the following might be of use to those of you who are still using Apache 2.0 with LDAP and wish to upgrade to 2.2. I found this basic information around online, but I had to search pretty hard for it. Perhaps presenting this in a more straightforward way might help the next searcher to find an answer more quickly. It's probably only of interest if you are using LDAP as your authentication system with an older Apache (e.g., 2.0) and have upgraded to 2.2 on an Ubuntu or Debian system (such as upgrading from dapper to gutsy.)
When running dapper on my intranet web server with Apache 2.0.55-4ubuntu2.2, I had something like this:
Many people don't realize that the GPLv3 process actually began long before the November 2005 announcement. For me and a few others, the GPLv3 process started much earlier. Also, in my view, it didn't actually end until this week, the FSF released the AGPLv3. Today, I'm particularly proud that stet was the first software released covered by the terms of that license.
In my previous post about Xen, I talked about how easy Xen is to configure and set up, particularly on Ubuntu and Debian. I'm still grateful that Xen remains easy; however, I've lately had a few Xen-related challenges that needed attention. In particular, I've needed to create some surprisingly messy solutions when using vif-route to route multiple IP numbers on the same network through the dom0 to a domU.
I tend to use vif-route rather than vif-bridge, as I like the control it gives me in the dom0. The dom0 becomes a very traditional packet-forwarding firewall that can decide whether or not to forward packets to each domU host. However, I recently found some deep weirdness in IP routing when I use this approach while needing multiple Ethernet interfaces on the domU. Here's an example:
Way back when User Mode Linux (UML) was the “only way” the Free Software world did anything like virtualization, I was already skeptical. Those of us who lived through the coming of age of Internet security — with a remote root exploit for every day of the week — became obsessed with the chroot and its ultimate limitations. Each possible upgrade to a better, more robust virtual environment was met with suspicion on the security front. I joined the many who doubted that you could truly secure a machine that offered disjoint services provisioned on the same physical machine. I've recently revisited this position. I won't say that Xen has completely changed my mind, but I am open-minded enough again to experiment.
Nearly all software developers know that software is covered by copyright. Many know that copyright covers the expression of an idea fixed in a medium (such as a series of bytes), and that the copyright rules govern the copying, modifying and distributing of the work. However, only a very few have considered the questions that arise when trying to determine if one work infringes the copyright of another.
Indeed, in the world of software freedom, copyright is seen as a system we have little choice but to tolerate. Many Free Software developers dislike the copyright system we have, so it is little surprise that developers want to spend minimal time thinking about it. Nevertheless, the copyright system is the foremost legal framework that governs software1, and we have to live within it for the moment.
I taught AP Computer Science at Walnut Hills High School in Cincinnati, OH during the 1998-1999 school year.
I taught this course because:
We went to the Curryfest last weekend which was pretty good. Of course we ended up spending most of the time with Emrys in the playpark with hundreds of kids.
I have just returned from a weekend at Station Creek with Ev. We hung out like …
I don't remember when it happened, but sometime in the past four years, the Makefiles for the kernel named Linux changed. I can't remember exactly, but I do recall sometime “recently” that the kernel build output stopped looking like what I remember from 1991, and started looking like this:
CC arch/i386/kernel/semaphore.o
CC arch/i386/kernel/signal.o
This is a heck of a lot easier to read, but there was something cool
about having make display the whole gcc
command lines, like this:
One of my biggest worries in using a laptop is that data can suddenly become available to anyone in the world if a laptop is lost or stolen. I was reminded of this during the mainstream media coverage1 of this issue last year.
There's the old security through obscurity perception of running GNU/Linux systems. Proponents of this theory argue that most thieves (or impromptu thieves, who find a lost laptop but decide not to return it to its owner) aren't likely to know how to use a GNU/Linux system, and will probably wipe the drive before selling it or using it. However, with the popularity of Free Software rising, this old standby (which never should have been a standby anyway, of course) doesn't even give an illusion of security anymore.
I needed to pick a small, inexpensive, 2.0-compliant USB hub for myself, and one for any of the users at my job who asked for one. I found one, the “CP Technologies Hi-Speed USB 2.0 Hub”, which is part number CP-UH-135. This worked great with GNU/Linux without any trouble (using Linux 2.6.10 as distributed by Ubuntu), at least at first.
A few days ago, I acquired a number of IBM xSeries servers — namely x206 and x226 systems — for my work at the The Software Freedom Law Center. We bought bare-metal, with just CPU and memory, with plans to install drives ourselves.
I did that for a few reasons. First, serial ATA (S-ATA or SATA) support under Linux has just become ready for prime time, and despite being a SCSI-die-hard for most of my life, I've given in that ATA's price/performance ratio can't really be beat, especially if you don't need hot swap or hardware RAID.
When I got the machines, which each came with one 80 GB S-ATA drive, I found them well constructed, including a very easy mounting system for hard drives. Drives have a blue plastic tray that looks like this (follow link of image for higher resolution shot).
Well, sugar crazy-kid-day is done. Been a bit slack with the blog, working too much of late, no excuse. I made a post-box yesterday with Oscar the Grouch on it, rather confusingly, he is saying, ‘No Junk’. I really need to think things through before …
Hmmm… sorry been rather busy lately. I’ve added a couple of photos of the Em and Choppy. Evan bottle fed Emrys today because Cheri had to go to the dentist. He was dead chuffed and seemed to be much better at it than me.
Tomorrow we are going to …
Dang! Yellow is ugly, I’l have to change the colour again. ‘scuse me while I go upstairs to get another glass of wine…
Aaaaagh!! this keyboard is wobbling, Evan is watching a disney (aka satan) movie called, “dinosaur” very loudly. Emrys is sleeping on my arm hence the one …
Emrys Tsambikos Tyler Joy
We have decided to include the name Tsambikos in Emrys’ name!! I might explain why later…
Oh and just in (on Charlies’ request), here is a snap of me with my new little boy (Unfortunately I’ve lost this photo)
I’m off to bed now …
Hmm before I forget…
Cheri was getting contractions on and off for a couple of days but they were not at all regular. Eventually at around 4 or 5 pm on the 27th of February, last Wedenesday they started to come with more regularity.
As they were still very gentle …
[ This essay was originally published on gnu.org. ]
When I was in grade school, right here in the United States of America, I was taught that our country was the “land of opportunity”. My teachers told me that my country was special, because anyone with a good idea and a drive to do good work could make a living, and be successful too. They called it the “American Dream”.
What was the cornerstone to the “American Dream”? It was equality — everyone had the same chance in our society to choose their own way. I could have any career I wanted, and if I worked hard, I would be successful.
It turned out that I had some talent for working with computers — in particular, computer software. Indoctrinated with the “American Dream”, I learned as much as I could about computer software. I wanted my chance at success.
My thesis is nearly complete. I defend tomorrow, and as usual, I let the deadline run up until the end. I just finished my slides for the defense, and practiced once. I have some time in the schedule tomorrow to practice at least once, although I have to find some empty room up at the University to do it in.
I'll be glad to be done. It's been annoying to spend three or four weeks here sitting around writing about perljvm, and not hacking on it. I have a Cosource deadline coming up this week, so now's a good a time as any to release the first version of the Kawa-based perljvm.
I am really excited about how Kawa works, and how easy it is to massage perl's IR into Kawa's IR. I got more excited about it as I wrote my thesis defense talk. I really think great things can happen with Kawa in the future.
Tonight, I finished the actual document of my Master's thesis. I had to vet it by reading it out loud, about three times. I have a real hard time finding subtle grammar errors. I believe that when I read, I parse them out in my head. Reading out loud usually helps, but it wasn't working so well this time. (The first draft had many errors, even though I read it out loud.)
This time, I went through it twice, reading it out loud while bouncing the mouse along each word. This seemed to help a lot, as I was catching errors left and right. I hope I got them all.
I sent the final document off to the committee. I haven't heard from Larry Wall, whose an external member of my committee, at all. I haven't heard from since we set up the plane tickets months ago. I am sure he's insanely busy, and that's likely why. No big deal, I suppose, I am just overly nervous.
Welcome to Tregeagle.
I have decided to revamp this site, so expect to see some major changes in the future. I have moved our training and computer help to rentageek which will be maintained by Matt and me.
I am going to return this site to its original path and …
On the original version of my website I wrote a long blether about Tregeagle. My version of his story, much of it inspired no doubt by that early Kneehigh Theatre production I saw at the Minack. Like much from back then it has been …