Several webloggers who use “cornerhost”: found themselves “suddenly relocated”: over the weekend (“for the record”:, it wasn’t really cornerhost’s fault).

cornerhost’s policy is that users are responsible for their own backups. Naturally, some people found out that this was true :-)

As part of the ensuing chaos, someone pointed out Mike Rubel’s article “Easy Automated Snapshot-Style Backups with Linux and Rsync”:

I’ve been a sysadmin for over 15 years. I’m a *big* fan of backups. (I’m _very_ unhappy that my tape drive is broken right now. :-) I’ve been doing nightly full backups of my servers using rsync for a long time, but the technique Mike uses for incrementals never occured to me (blush). A minor change to a couple of scripts was all it took for me to have a week’s worth of snapshots on the backup hosts. Fabulous!

Thanks, “Mike”:!

posted at 9:32 am on Wednesday, April 30, 2003 in Site News | Comments Off on Backups

Homepage update

Prompted by “an entry”: on “Kasia’s weblog”:, I started updating “my bio”:, and ended up completely revamping (and substantially simplifying) “my homepage”: . It was fun, and a good way to absorb coffee after my son woke me up too early this morning…

posted at 9:45 am on Saturday, April 26, 2003 in Personal | Comments (1)
  1. Reid Ellis says:

    The “people” link at the bottom of your bio is on the fritz.

    Ya, i was ego-surfing, so sue me. :-)

WISH 44: Picking Games

Perverse Access Memory: WISH 44: Picking Games

I’ve been reading PAM (and its predecessor) Since about WISH 27. This week’s question prompted me to finally answer one. At some point I’ll go back and fill in other interesting ones.

bq. How do you choose games to join or to run? What factors influence you: timing, people, system, genre, etc.? Do you weigh different factors for different kinds of games, e.g., online vs. tabletop vs. LARP? Is it a group decision or a decision you make on your own?

The overwhelming factor in my life is time, althought this manifests in several ways.

I’ve been gaming for about 17 years now. I’ve only played in a few ongoing games, because I can barely find the time for one campaign at a time; I’m forced to be selective. They’ve always been tabletop games; I’d love to try a PBeM game sometime, but I haven’t found one I think I’d like enough to commit regular (weekly or better) time to. LARP isn’t for me; I’m a technician, not an actor.

My current Rolemaster campaign has been running for 5 years, and the 2300AD campaign before that was longer. I like long running campaigns. If I’m going to commit the time to develop a character and explore a world, I want it to be a going concern, not a simple dungeon crawl or two (those are fun, but I prefer single day, tournament style for those). It takes a long time for me to develop and then flesh out a character, and I do that best inside a campaign, interacting with the world and my fellow characters.

I like games that meet regularly, but not too often. Both of my campaigns tried meeting weekly, but ended up with longer monthly sessions instead. My fellow gamers (and our spouses) are willing to commit _one_ day per month to gaming, and schedule other things around Game Day. With a weekly meeting, we’d always have someone away, making continuity difficult.

I don’t have a strong preference for any particular system. I’ve played AD&D, Champions, Traveller, 2300, GuRPS, and now Rolemaster. There are two exceptions though; I like the magic system in Rolemaster much better than in any other system I’ve tried, and I love the simple task resolution system in MegaTraveller and 2300AD.

What this really means is that I’ll play whatever game system (and genre/setting) that the GM wants to play. That’s how I got into all of the games listed above; the GM wanted to run a particular game, and asked for players…

I’ve played several genres, but I like classic low-tech, fantasy realms with magic the best. When I play SF or superheros, I tend to play myself in a spacesuit (or in a cape) In fantasy worlds I can dtop into a character more easily.

People are the second most important factor for me. I strongly prefer gaming with people I know, and preferably people I know well. That limits my options, even though about half of the Gang are roleplayers. There are just too many opportunities for strife and discord in gaming environments; getting to know a new group of people is risky given my time restrictions.

In short, roleplaying done right is a large time commitment, and as I don’t have a lot of free time, I’m forced to be selective. A good GM and a good bunch of players (usually my friends) are the biggest consideration for me. After that, whatever the GM wants to run is fine by me!

posted at 4:02 pm on Friday, April 25, 2003 in Gaming, WISH | Comments (3)
  1. Arref says:

    Sounds like you are a “classic mature gamer”. Your point about “willing to commit one day per month to gaming” is one I neglected to talk about.

    Good show.

  2. Arref says:

    really like your clean blog design

  3. RJ says:

    Harald in a spacesuit & cape.

    The mind boggles.

SMTP works just fine, thank you

“Joel on Software”: → “Internet Security: Too Broke to Fix?”:,3973,1036052,00.asp

Larry Seltzer wants to replace SMTP with something that has authentication and resource limits. Well, SMTP already has authentication, and many MTAs already have resource limits…

Many people discover SMTP’s authentication when they try to send e-mail while travelling; their ISPs don’t let them. SMTP can already use TLS with certificates, SASL, or POP-before-SMTP, and many ISPs are starting to require one or more. My _hobby_ server supports all three, so it can’t be hard. I haven’t seen anyone do resource limits out-of-the-box yet, but that’s because it doesn’t really solve anything; spammers will always be able to hide inside “legitimate” usage profiles.

The problem is not the protocol, or the mythical “Internet”; it’s poorly administered computers. People who don’t think twice about _properly_ managing and securing a PBX will turn around and install, then neglect, crappy SMTP gateways. In my e-mail logs, the worst offenders for poorly administered servers are non-technical companies (law firms, insurance companies, banks :-). Most of the spam I receive comes through open relays on corporate networks, and through relays on home computers (where Microsoft installs insecure software direct from CD :-).

If we introduce a new protocol, spammers will find new ways to abuse it. Criminals are constantly finding new ways to abuse corporate PBXes, and cell phones, and calling cards. The solution is for people to stop treating the Internet as a toy, and start maintaining their servers properly. Sadly, that’s not likely to happen, and so we’re left with reactionary technology like realtime blackhole lists and desktop spam filtering software.

posted at 3:43 pm on Friday, April 25, 2003 in Rants | Comments Off on SMTP works just fine, thank you



I think it’s time to check the basement for pods?

posted at 9:41 pm on Tuesday, April 22, 2003 in Current Events | Comments Off on Wha?

Weight Watching continued

So I’m four weeks into Weight Watchers’ maintenance program. The idea is that you try to be consistent (so that your weekly weigh-ins are reasonably accurate), and add points to your daily regimen until your weightloss flattens out.

As you can see from the new graph on the left, I haven’t flattened out yet. Instead, I’ve lost another 4.6 pounds; in fact, I’m losing _more_ weight now than I was in the last month of my regular program, even though I’m eating more. Frankly, I’m confused :-). I don’t think I’ve significantly increased my activity level; I haven’t started my formal spring exercise program yet, and I’m a week off curling now.

One theory is that I wasn’t eating _enough_ on the weightloss regimen, and so my body was hoarding calories; now that I’m eating more, my metabolism has increased? I dunno; that’s merely a SWAG (scientific wild-ass guess). Ah well, I’m going to try not to fret, and just enjoy eating some of the things that I didn’t have enough points for before…

posted at 1:41 pm on Monday, April 21, 2003 in Personal | Comments (1)
  1. aep says:

    Oh no! The experiment has gone horribly, horribly wrong and you’ve become the Incredible Shrinking Harald! At this rate, you’ll weigh 0 lbs sometime in June 2005.

Playing with Time

“”: → “Playing with Time”: :

bq. “Playing With Time”: is an exciting, new project that looks at how the world around you is changing over many different time periods.

bq. Here at the “Playing With Time”: web site, unseen worlds of change will be revealed. You will see time sped up and slowed down, and behold the beauty of change.

I have always been intrigued by visualisation techniques; manipulating time is another one. Taking ordinary events and speeding them up or slowing them down often reveals existing patterns that we cannot normally perceive.

“Playing With Time”: has both fast motion and slow motion movie clips revealing a variety of changes. I particularly like the shots of the same location on several different time scales; you can watch the clouds move over a period of minutes, or see the tide roll out, or see the grass grow and die over a year. Fabulous stuff, and worth a visit.

posted at 11:13 am on Friday, April 18, 2003 in Favourites, Links, Science and Technology | Comments Off on Playing with Time

Good Weather and 802.11b

So I’m sittin’ on the Group W bench…

No! I mean I’m sitting on the front porch, reading e-mail and writing this blog entry; my daughter (home from school today, remember?) is playing on the sidewalk. We’re waiting for the towels and swimsuits to dry, so that we can pack them up and head to the park for the rest of the afternoon before swim class.

It’s _summer_ out here, about 25°C and _sunny_. It’s only going to last today, apparently; tomorrow’s forecast is for a high of 16°C in the morning, them falling to 0°C with a freezing rain warning, so I’m enjoying the weather while it lasts.

I’ve discovered that my 802.11b only works with the front door open. It is steel; apparently it blocks just enough of the signal from the hub when it is closed. Defintely time to move the hub from the basement to the living room :-)

It’s a rough life, I know.

[ Update: it didn’t get that cold, and no freezing rain… ]

posted at 2:33 pm on Tuesday, April 15, 2003 in Personal | Comments (2)
  1. Reid Ellis says:

    Hey, you missed a ‘;’ in one of your ”&deg”s.

    Btw, I *really* like the new page layout. How does it look under Netscape 4 et al?

  2. Harald says:

    I’ve tried IE6 and Mozilla. IE5 has some minor problems with CSS, but I don’t think I trigger any of those bugs. I’vealso tried it without a stylesheet, and it is presentable.

    It’s presentable in my old Netscape 4.7 at work (the same as no stylesheet at all), but I haven’t tried any of the Mac browsers :-)

    Im glad you like it. It started as a proof-of-concept (the floating titles) and progressed into a full-fledged re-vamp. I cleaned up some of the HTML in the process, and there’s more I want to do there, but it’ll have to wait for another day…

Vigorous exercise required

A new somewhat controversial study has been performed by scientists at Queen’s University in Belfast, Northern Ireland, and published in Heart (a British Medical Journal) concludes that only vigorous exercise combats the risk of early death from heart disease:

‘Moderate exercise’ not sufficient

bq. a new study published today said moderate exercise such as a brisk walk five times a week has no impact on the risk of dying from heart disease.

bq. The study authors concluded that regular exercise does have profound effects on health.

bq. But only vigorous exercise seemed to have any impact on the risk of an early death from heart disease.

I’ll take the second last paragraph to heart :-)

And from “CBS News”: :

bq. One drawback of the study, the scientists acknowledged, is that the men only were questioned about their exercise habits one time at the start of the study, so there is no way to know whether the men changed their habits over the 10 years the study was conducted.

bq. Studies that compare different intensities and patterns of exercise, but keep the number of calories burned equal, likely will provide stronger insight into the question of exactly what is required for heart health, Blair said.

bq. He said the superiority of the vigorous exercise might simply come down to the fact that it burns more calories than moderate exercise.

I can’t see anywhere if the study considered people who perform _no_ exercise; many of the “30 minute a day” studies compare against couch potatoes, where there’s a clear superiority. I also wonder if the study accounted for dietary differences; people who consider exercise important also tend to eat better.

Ah well; publish or perish is the rule, and publishing a controversial study certainly gets your names on the Internet :-)

posted at 9:06 am on Tuesday, April 15, 2003 in Health | Comments Off on Vigorous exercise required

Sick Kids

Well, ok, one sick kid.

Charlotte got up yesterday morning and started throwing up, even with no food in her. It’s amazing how pathetic she looks when she’s sick; she looks just like her grandmother :-). Every time she fell asleep she would feel sick again, wake up, and vomit. When we started seeing traces of blood we took her to the local pediatric clinic…

It turns out that it’s fairly common for 4-year old children to develop esophogial tears when they vomit a lot. Still, the doctor did all the usual tests, and sent her home to clear fluids (and no school on Monday). One dose of gravol later, and she slept the entire afternoon away.

Turns out the doctor made a good call; she has (Group A) strep. Time for antibiotics, and another day off school. Charlotte’s enjoying all of the attention, I think :-) It’s a good thing she _loves_ Jell-O!

It’s amazing how disruptive one throat infection can be. Michaela was supposed to work today, but is home with Charlotte instead. She moved her work day to Tuesday instead (bumping a job interview to first thing Wednesday morning), so I have to stay home tomorrow. Should be fun…

posted at 1:15 pm on Monday, April 14, 2003 in Personal | Comments Off on Sick Kids

Miscellaneous System Notes

“Greg”: has a few new students starting this summer. Time to update the default user profiles and “create new account” software to make this easier, since I do it so seldom and keep forgetting all of the steps. I’m thinking of either using LDAP or MySQL for authentication, or finding an /etc/passwd based auth module for Apache and samba; either would let me use the same passwords everywhere on the system.

I recently converted from “uw-imap”: to “courier-imap”: Courier uses maildir instead of mbox format. Webmail is now much faster, since IMAPD does not lock and parse the entire mail spool for every web-click! OTOH, this means no more mail(1) or pine; aw, shucks.

I’ve been cleaning up the “main CFRQ page”: and the top-level stylesheet a bit. Not really sure why, or where I’m going with that-which-loosely-qualifies-as-a-design. I also finally got the default “VirtualHost”: (“”: working again, so I think I’m going to move all of the local stuff (and that installed by “RedHat”: back to that page, and then replicate it to “hermione”:

posted at 2:48 pm on Sunday, April 13, 2003 in Site News | Comments (2)
  1. Reid Ellis says:

    Are there any imap daemons that use MySQL for mail? And, if there are, are there any command-line clients that can parse/use these mailboxes?

    Hm, one reason I like mbox format is that I can burn it to CD and read it with software 20 years later without a problem. Maildir is what (ex)mh uses, right? Where a mailbox is a dir and messages are files? Sort of like seeing your mailbox explode. :-)

    That would be fine with something like rfs, which is optimized for small files, but I think it would kill ext2 if you have huge mailboxes (which I do — several over 1000 messages).

    I guess for archival, if I had some SQL thing, I could have a script that spit everything out in mbox or something..

  2. Harald says:

    I’m sure there are software packages out there that store e-mail in a MySQL database; I haven’t researched that specifically. Google is your friend :-)

    My archived mail is currently 507Mb (wow!), in 47450 files (with a couple of control files in each folder, I have slightly fewer actual messages). In practice, I don’t have any trouble with using MH format; EXMH as a GUI hides that detail, and the MH/NMH command line tools are very easy to use (they were designed that way, after all).

    Maildir format is a little weird; the filenames are long and somewhat unintelligible, so using standard command line tools is more challenging. I’ve eneded up with a few perl/python scripts to make life easier.

    Mutt speaks maildir format directly, as does courier IMAP; between the two, it’s easy to manipulate my mailboxes. Also (as you mentioned) I keep my primary mail on my laptop in MH format; the maildir stuff is a) for other users that use IMAP and/or webmail, and b) for when I’m travelling and using webmail instead of my laptop.

The Monty Hall ‘Paradox’

“The Blog of Jvstin”: → “Ones and Zeros”: → “Nail Tinted Glasses”: → “Dean’s World”:

The Monty Hall problem is simple:

bq. You find yourself on a game show called “Let’s Make A Deal.” The game is very simple. There are three doors: door #1, door #2, and door #3. Behind one door is a million dollars. The other two doors contain worthless joke prizes. All you have to do is pick which door you want to open, and you get whatever is behind it. But you only get to open one door. By simple math, then, you obviously have a 1 in 3 chance of picking the correct door and becoming an instant millionaire.

bq. You pick a door. As soon as you tell Monty (the gameshow host) what door you want to open, he stops and says, “Okay, you’ve made your choice. Now, I’m going to do what we always do here on this game. I’m going to open one of the other two doors for you that I know has a booby prize.” And he does so. Then he asks, “Okay, now, would you like to stay with your original guess, or would you like to switch to the other door that’s still closed? You only get one shot, so do you want to stay with your original choice, or switch?”

bq. Here’s the question: is there any compelling reason to switch doors?

The answer is surprising!

posted at 1:39 pm on Thursday, April 10, 2003 in Odd | Comments (9)
  1. Reid Ellis says:

    I just think of it this way: the first choice you made had a 33% chance of being correct. Switching to the other door increases your chance to 50%. Pretty simple, really.

  2. Claudia says:

    You can look at it a much simpler way.

    Suppose you chose door one. Monty opens door three and there is a goat. So you swap to door two. YOU WIN!!!

    Suppose you choose door two. Monty opens door three. You swap and YOU LOSE!!!!

    Suppose you chose door three. Monty opens door one you swap and YOU WIN!

    These are the only possible senarios and in 2 of them you win.

    Just forget everything you know and it makes sense

  3. Big Bob says:

    There are two scenarios:

    1. Pick the correct door(1/3 of the time). Monty opens either of the other doors. You switch, you lose.

    2. Pick an incorrect door (2/3 of the time). Monty opens the only other losing door. You switch, you win.

  4. Michael says:

    Here’s the way I look at it (it’s sort of a before/after point of view):

    If there are three cards to choose from we know that there is a 33% chance of winning. But, when big Monty reveals a goat door, that eliminates one possibility from the scenario, because the contestant knows not to pick that door. So then there are two doors left. Forgetting all context, one knows that 50% of all those two doors wins – switching or no, thats the new probability of winning. – but this isn’t my point of view, because this alone still doesn’t seem right to me.

    I view it as an equation, if you will, in which a variable, the door chosen by the contestant, is to be identified as winning or not. In the beginning, there are three possibilities: losing door A, losing door B, and winning door; therefore, we are 33% sure of the door’s identity. When Monty reveals a losing door (A or B, like we care), there are only two possibilities left – we’ll say losing door B and the winning door. Now the equation is simplified a step and we’re 50% sure of the door’s identity. Finally, Monty reveals the chosen door (simultaneously eliminating the other door, making only one possibility), and we know (100% sure) that it’s either the winner or loser B. No switching is required because that doesnt change the number of possibilities available, it just kinda symbolizes that one of the two possibilities was chosen.

  5. James in LV says:

    This paradox is great…but Claudia’s post shows how a person walked right into it’s trap. After Monty has opened one of the doors, you have a new choice to make. Therefore, all odds are reset to the new decision at hand. It really isn’t a matter of *switching* doors either because you can simply say you haven’t even selected a door at all yet. Since a new choice has to be made among two doors, it’s simply a 50% chance. The trap is assuming that you have to *swap*, in which case Claudia’s analysis above appears correct.

  6. Michael H. says:

    James’ comment reflects the common intuition, that after Monty opens a door to reveal a booby prize, the two remaining doors are equivalent (i.e. there’s a 50% chance with either door). That intuition is wrong, which is why this is called a paradox.

    Big Bob had it right. Your original choice is only right 1/3 of the time, so it makes sense to switch after Monty opens one of the other doors. The odds are 2/3 that the money is behind one of the doors you didn’t pick. Monty gives you some really useful information by eliminating one of those doors. The odds are still 2/3 that the money is behind one of the other doors, but now one of those doors has been eliminated for you.

    Consider this: if it were equally good to switch or stick with your original door, then you could stick with your door and be right 50% of the time. That means that, presented with 3 doors, you can pick the right one 50% of the time. Nice work, Kreskin!

    Or consider this: Instead of 3 doors, there are 100. You pick one, then Monty opens 98 of the remaining 99 doors, to reveal nothing but booby prizes. Would you stick or switch to the other unopened door?

  7. Michael H. says:

    There’s a very nice explanation of this paradox — and even a chance to play the game — at:

  8. Harald says:

    Thanks for the link!

  9. T. Bishop says:

    Consider the possibility that Monty is malicious, and only gives the option of switching if the original guess was correct. (He’s lying when he says “I’m going to do what we always do here on this game.”) In this case, it’s always a mistake to switch.

First Toronto, now Ontario?

“GeoURL”: → “ThatGrrl”: → “Bloggers of Ontario Unite!”:;action=list .

Now to find Canadian bloggers, and I’m all set… :-)

posted at 11:08 pm on Wednesday, April 09, 2003 in Links | Comments (1)
  1. Luke Reeves says:

    Heh, GeoURL is exactly how I found your site :-)

Life in Space

Space Station Science Picture of the Day: High Tea

I wish NASA would do more of these “life in space” bits. They’re fascinating, and there is a lot of interesting science hidden away in them.

How do you drink tea in zero-G? with chopsticks, of course! How do you make sure your can of honey doesn’t float away? put a drop of water on the bottom, and use surface tension to stick it to the table! This, and more, can be found in the videos at the bottom of High Tea

posted at 5:14 pm on Tuesday, April 08, 2003 in Links | Comments Off on Life in Space

GTA Bloggers

Six months ago Google and I couldn’t find very many Toronto weblogs. Today, while reading a fascinating story, I discovered the Greater Toronto Area Bloggers site.


(go read that fascinating story, btw. Nothing I could say captures it.)

posted at 2:52 pm on Tuesday, April 08, 2003 in Links | Comments Off on GTA Bloggers

Mad Scientist or Evil Genius?

Gareth wants to be a Mad Scientist; I think he’s already well on his way. But with the role models he’s got, it could easily be Evil Genius instead… <grin>

posted at 12:53 pm on Saturday, April 05, 2003 in Personal | Comments Off on Mad Scientist or Evil Genius?

I’m not the only one playing with technology

In “Bits and pieces [dive into mark]”: , Mark writes that he has installed an OpenLDAP server and software to manage his contact lists, “For fun”.

bq. (In 1995, my dog had an e-mail address and a home page; in 2003, she was the first entry in my LDAP directory. This we call progress.)

Sounds exactly like something I would do. is primarily an excuse for me to play with technology, after all. (In fact, stay tuned; LAMP ganglist software is currently undergoing a security audit on my laptop :-)

posted at 12:21 pm on Tuesday, April 01, 2003 in Odd | Comments Off on I’m not the only one playing with technology


It’s snowing. A lot. The roads are treacherous.

Happy April Fool’s Day…

posted at 9:13 am on Tuesday, April 01, 2003 in Odd | Comments (1)
  1. James says:

    It’s snowing alots? Watch out, because those things bite!