Today's APOD photo is a very cool shot of Saturn taken from the rapidly approaching Cassinni probe. With arrival at Saturn scheduled for July 1, I'm looking forward to some exciting pictures and science in the coming months.
My friends have entirely too much time on their hands. :)
Our hospital mail servers are being hit pretty hard with a nefarious virus that claims to be from the networking team. It's making email unpleasantly slow.
The first message I got came from the hospital-wide broadcast email address, just a :-) in the subject, "I don't bite! Password: 53321" and an attachment masquerading as a zip file. Naturally the first thing I did was delete the message, since didn't even remotely resemble anything that typically comes from the broadcast email address. Apparently, others did not think about the message as much and now chaos is ensuing.
There's also been a similar one claiming to be from the IT group about accounts being deactivated.
Subject: E-mail account disabling warning. Dear user of xxxxxxx gateway e-mail server, We warn you about some attacks on your e-mail account. Your computer may contain viruses, in order to keep your computer and e-mail account safe, please, follow the instructions. Advanced details can be found in attached file. In order to read the attach you have to use the following password: 35151. Best wishes, The xxxxxxxx team
So I've been getting about 4 or 5 emails every minute from various people I've never heard of on campus. Ironically, most of the messages aren't propagated by the virus...instead they're coming from people responding to the initial virus message saying stuff like "Why am I getting this", and people responding with stuff like "I don't know why I'm getting this either". Then these people click "Reply to all", so not only does the original sender get a response, but the entire hospital has to see the same message too, since the broadcast email address was in the From header.
So now hospital email (Groupwise) is all but useless because the mail server is bogged down with virus email, people responding to virus email and people responding to people responding to virus email.
Ugh
You are Rerun!
Which Peanuts Character are You?
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via Cornelia
After several months of waffling, watching and just general procrastinating, I finally took the plunge and upgraded the database server on my Sparc20 from MySQL 3.23.58 to 4.0.18. It wasn't exactly trouble free, but wasn't as much work or as difficult as I thought it might be.
Step 1: Create an SQL dump of all the databases: mysqldump -A -u user -p > dbdump.sql
Step 2: Shut down MySQL
Step 3: Run mysql_install_db from the MySQL4 installation
Step 4: Start up MySQL4
Step 5: Use the database dump created in Step 1 to restore the databases: mysql -u root < dbdump.sql
Step 6: Change password on MySQL root user and recreate database users.
Went pretty smoothly with a 30 MB dump file. There are probably easier ways, but this method seemed more straight forward.
Ended up losing a couple of tables because of column names conflicting with MySQL4 reserved words. Fairly easy to fix though. Just took time to go through all the databases and compare the tables to the dbdump.
So, next task is to learn about all the new things in MySQL 4. Then the next big thing will be to repeat the upgrade process on my main production server. I figure by the time I get around to that, MySQL 5 will be the production release :).
I suppose one of these days, I shall have to get around to fixing that problem with the side bar where it spreads out at the bottom of the page for short entries. That means I'll have to get around to learning CSS. Just another item on my List of Things To Do.
Maybe I'll just do away with the side bar on the archive pages. Or maybe I'll just make a shorter version of the sidebar to use on the archive pages. More things for my List.
What was...
1. ...your first grade teacher's name?
Mrs. Shamchuck. I even went to her retirement 12 or so years later.
2. ...your favorite Saturday morning cartoon?
Superfriends
3. ...the name of your very first best friend?
Derek
4. ...your favorite breakfast cereal?
Honeycomb
5. ...your favorite thing to do after school?
Go out and play.
Ok, I haven't finished writing up my thoughts on the last paper, but that's just because I've been lazy. It was interesting paper, and I learned a few things. Still skeptical though. But more on that later.
This week's article comes from Medical Physics and is titled "The impact of increased Al filtration on x-ray tube loading and image quality in diagnostic Radiology" by RH Behrman (Med Phys 30, 69-78 (2003)).
When I was an undergrad (way back in 1991), one of the projects I did (and the first one I did in Medical Physics) for my 4th year physics lab course was to study dose reduction to pediatric patients undergoing cardiac catheterization procedures. My lab partner and I looked at reducing radiation dose by adding a copper filter at the x-ray tube. So this paper was of particular interest to me. Added filtration significantly reduces low energy x-rays that don't contribute to image formation, but then you need to compensate by boosting the x-ray technique.
Most fluoroscopy systems now come with automatic systems that add or remove filters of various types depending on the amount of radiation received at the receptor. Good for the patient, but harder on the generator and x-ray tube. I also suspect that the added filtration also leads to increased scatter exposure to the doctors performing the procedure. Since the added filter increases the effective energy of the x-ray beam, and Compton scatter increases with energy, there should be more scattered radiation This is one of the things I've been wanting to study for a while (one of the many research project ideas gathering dust in the back of my brain). Maybe I should find a way to get a summer student or something to work on this with me.
Abstract:
Previous work has shown that for nine common radiographic projections (AP abdomen, AP cervical spine, LAT cervical spine, PA chest, LAT chest, AP hip, AP lumbar spine, LAT lumber spine, and AP pelvis) increasing the total x-ray tube filtration from 2.5 mm Al equivalent (the regulatory minimum for general diagnostic radiology) to 4.0 mm Al equivalent, reduces the average effective dose and average skin entrance dose by 9% and 16%, respectively, using a 400 speed screen-film system.1 In this study, the effects of this filtration increase on x-ray tube loading and image quality were assessed. For the above projections and filtration increase, mean absolute and percentage increases in tube loading were 2.9 mAs and 15%, respectively, for a constant film density and fixed kVp. Tube current (mA) increases of 25% (a worst case) resulted in no statistically significant loss in focal spot resolution due to blooming for both large (1.2 mm) and small (0.6 mm) focal spot sizes, except at high mA low kVp techniques. The latter losses were below 10%, and when the image receptor blur was incorporated, the total system spatial resolution losses were on the order of one-quarter to one-half these values for typical clinical geometries. Radiographs of a contrast phantom taken with 2.5 and 4.0 mm total Al equivalent x-ray tube filtration were compared at 60, 70, 81, 90, 102, and 121 kVp. No statistically significant changes were observed with regard to (1) test object conspicuity as reported by three observers, (2) image contrast, as measured using a densitometer with a 3 mm aperture (±0.0017 OD, 95% confidence level), and (3) pixel value image noise, image contrast-to-noise ratios, and image signal-to-noise ratios, as measured using a scanning densitometer with a 12-bit acquisition depth and 85 µ pixel size (±2.5%, ±3.1%, and ±2.5%, 95% confidence levels, respectively). These results, combined with the linear no-threshold model for radiation risk and the ALARA principle, suggest that general radiography should be carried out using a minimum of 4.0 mm total Al equivalent filtration. ©2003 American Association of Physicists in Medicine.
The researchers used a pair of homemade Helmholtz coils to produce magnetic fields and exposed rats to a 0.01 mT field (Earth's magnetic field averages about 0.05 mT (50 µT) with significant regional variations) for 24 and 48 hours. The rats were sacrificed, the brains extracted and studied for single and double strand DNA breaks and apoptosis/necrosis using gel electrophoresis techniques.
Statistically significant differences were found in the number of DNA strand breaks between the exposed rats and control rats. Free radical production with NO and Fe+ ions were theorized to be the cause of the DNA strand breaks. Cell apoptosis was also found to increase following exposure. Experiments where the rats were administered free radical scavengers showed no difference between exposed and control rats. What remains to be seen, and what was not addressed in the paper is what kinds of health effects these breaks might have. This would probably be a difficult study to perform, since it would require studying a large number of rats over a long term to detect what is probably a very small effect.
Also not studied was the effect of DNA repair. The authors have clearly established free radical production as one mechanism of DNA damage in brain cells. But as is well known, cells are very good at repairing DNA damage. How much of the damaged cells would be repaired after 24 or 48 hours post-exposure? How significant would the loss of the cells be if the DNA could not be repaired and the cell died? What types of cells were most likely to incur damage? Since Fe+ free radicals were thought to be most likely involved, the authors felt that cells with higher Fe uptake would be more susceptible to damage. Authors also mentioned increased risk of neurodegenerative diseases, ALS, Alzheimer's and Parkinson's reported in previous literature due to occupational magnetic field exposure.
A few days ago, I noticed several referrals to this weblog from Physics Today while browsing through the server access logs. Had a quick look, and didn't see anything pointing to my weblog right away.
Looked again later on after seeing a few more referrals, and then I saw it in the Web Watch (subscriber sign-in required) section of the March issue! There it was, a link to my weblog! Web Watch is a little side column in Physics Today that highlights 2 or 3 interesting physics related websites. Have no idea how my weblog ended up there or even why since I haven't really put much of any physics content here yet, aside from my Journal club postings. But still, very cool.
For those of you who don't have access to the latest issue online and just can't wait for it to show up in your local library, here it is.
http://blog.imabug.netEugene Mah, a medical physicist at the Medical University of South Carolina, keeps a daily weblog called IMABLOG. With a soupçon of physics, Mah logs the minutiae of his daily life and reflects on the world in general.
Coming today to APOD, the newest deep space photo from Hubble, the Hubble Ultra-Deep Field image. The Hubble Deep Field showed hundreds of galaxies in an area previously thought to be dark and empty. Now, with the HUDF containng data from over 400 orbits looking at the same region of space over a 3 month period, I'm sure there will be even more to see, looking even farther back into time.
Lots of cool juicy info in the STSI newsletter
My wife hasn't even started med school and already she's carved out a piece of my office for her to use. She's moving into my office and redecorating. She's already planned out where I'm supposed to have shelves installed, where to relocate my filing cabinets, printer and other computer bits and which bookshelves she's going to take over. I think my car is the only personal space I have left now...
I really hate it when I walk into the men's bathroom and find all (or most) of the urinals filled with yellow water. It's just gross. And sometimes, if it's been a while, you walk into the bathroom and get assaulted by the odour of stale pee left in the urinal. Eewww.
What's even worse is when I'm doing my business, and the other guy finishes his and leaves without so much as a flush or attempted flush. Sometimes he'll give a quick whack to the handle, which is completely ineffective. And it's not like they don't know it didn't flush properly. Urinals make distinctive noises when they're flushed successfully. A quick yank on the handle and a little bit of water dribbling down does not a flush make, and definitely does not make that distinctive sound.
Guys, I mean really, is it that difficult to push the lever or button to flush after you're finished? Let the water flow and run your own waste water away. Leave a nice mostly clean urinal for the next guy. Do you leave your toilet at home unflushed after doing your business? Are you trying to mark your territory and lay claim to the bathroom? Is the next guy supposed to walk in, smell stale pee and think "Oh, this one belongs to someone else...I'd better find another one"?
I mean, I know guys are supposed to be gross and disgusting creatures, but really. Flush, please! It's not that hard!
According to this Geek Test, I'm only 35.30572% geek, which ranks me as a Major Geek. It's a long quiz, with lots of questions. Not sure that some of the questions are entirely indicative of someone's geekiness. The review here pretty much echoes my thoughts about the quiz. My favourite badge of geekhood remains the Geek Code.
Found via Geeks WIth Blogs and From The Soup To The Nuts.
1. What was the last song you heard?
One by Shania Twain...can't think of what the title of the song was.
2. What were the last two movies you saw?
In the theater? Cold Mountain and Lord of the Rings: Return of the King.
On video, Spirited Away and ... oh rats, can't remember the name of it now...
3. What were the last three things you purchased?
Umm, bought groceries the other day, dinner at Sonic last night (wife's choice, not mine...she gets cravings for these kinds of things) and gas for my car.
4. What four things do you need to do this weekend?
Pick up a cake and fruit plate from the grocery store, get organized for a party, clean the apartment and call my folks.
5. Who are the last five people you talked to?
Wife, 3 people from work, and a lady walking her dog last night.
My wife decided we needed to have a big party to celebrate her getting into med school, and tomorrow's the big day. She's been planning it for a couple of weeks now, getting the catering, making invites, and all sorts of other arrangements. She likes doing this kind of thing, planning and organizing things. Should have seen her planning for the wedding.
My job for tomorrow is to pick up the cake and a fruit plate from the grocery store. For tonight, there is more apartment cleaning and lots of cooking. Planning to make up a big pot of greens (still don't know how anyone can eat that stuff) and a couple of pans of macaroni and cheese (mmm, yummy) to go along with the Sticky Fingers catered stuff. Lots of people, lots of food and hopefully lots of fun to be had.
Wow, is this sweet or what. A 400 GB Hitachi Deskstar hard drive in a 3.5" form factor. SATA and ATA interfaces too. And to think, just a little while ago I was happy as a clam when I stuck the 160 GB drive into my computer. Now with just 3 drives, I can have over 1 TB of storage at my fingertips.
The specs look reasonably decent. 8.5ms seek time isn't great, but for something this size it's not bad.
Let's hope that Hitachi's fixed the early drive failure problem that IBM was having with the Deskstar line.
Found at Slashdot.org
Hmm, they're back. And all from the same IPs the last few days (213.91.217.14, 213.91.217.15 and 213.240.200.127). Just today I've had to dump 3 comments that made it past the blacklist. It caught 6 of them in the past two days though. Added the domains to the blacklist, so they shouldn't be back. Think I'll have to work on some regexps to broaden the blacklist.
I have to question the intelligence of these guys. You'd think after they were blocked once, they'd get a clue.
Now, where did I put that cannon...
If you...
1. ...owned a restaurant, what kind of food would you serve?
Real authentic chinese food, with dim sum service on weekends.
2. ...owned a small store, what kind of merchandise would you sell?
The kinds of things you might stop to buy on the way home, or in the middle of the night. Snacks, TP, diapers, drinks, batteries, that kind of thing.
3. ...wrote a book, what genre would it be?
Hmm, sci-fi or fantasy I think.
4. ...ran a school, what would you teach?
Physics, of course.
5. ...recorded an album, what kind of music would be on it?
Probably instrumental stuff.
A while ago, my wife was filling out this scholarship application online that involved writing some paragraph long answers to various questions. One of the questions went along the line of "What piece of advice would you give to high school students" or something like that.
So it got me thinking, what kind of advice would I give? It's harder than you might think. After all, how do you give advice to an age group that thinks they know everything. Yes, you've all been there. How much advice did you listen to or take when it came from pepole older than you? Probably very little of it I bet.
So here's the advice I would give to high school students.
Listen to the advice people give you.
You're going to get a lot of advice from different people. Some older than you, some from your peers. Most of it will sound like crap, particularly when it comes from people older than you (like your parents). Just listen to it. You don't have to take it, just listen to it and consider it. No, we are not trying to control your life, order you around or tell you what to do (well, maybe your parents are). Just trying to pass along a little of our learned wisdom. After all, those people used to be your age, and have gone through many of things you are going through, and will go through. They know stuff. And in a few years, you will know stuff too, and you will have the same advice to give to others. Then you'll realize that yeah, we do know stuff, and that was some good advice we gave you and you're glad that you took it (or else you'll say "Man, I should have listened and taken that advice").
Hmm, just noticed that my weblog looks like crap under Netscape 7. It's mostly ok in IE 6. Looks just fine in Mozilla/Firefox. I must have style sheet and DIV issues. Wish someone would tell me these things.
POPFile 0.21.1 got released a little while ago, and I noticed it supports storing it's word corpus in an SQL database. So I decided to try it out and upgraded a few days ago. A relatively painless procedure documented here.
Just had to install Perl on my Win2K box (ActivePerl from ActiveState) and install a couple of modules.
POPFile with the MySQL backend runs a slower than it did using the flatfile BerkeleyDB. My machine running MySQL isn't the fastest in the world, so I blame it. I imagine it would be significantly faster with the DB server running locally.
Having the corpus and word matrix stored in an SQL database makes it easy to see what's going on. You can see what words have been classified, what buckets they belong to and how many times they occur. Makes it easier to dig out some statistics (if you want to do such things) about POPFiles word classification.
There are a few other changes to POPFile that make the 0.21.1 upgrade worthwhile. Switching to a MySQL backend from the default involves a little more work, and if you don't care about it, stick with the default.
If spam is a problem for you, and you want something simple to help manage it, I definitely recommend POPFile. Since the upgrade, POPFile's gone through 3000+ messages with only 24 misclassifications so far.
Now if only I could get my Groupwise mail to go through POPFile also...
One of the main reasons to read papers is to learn things. Preferably new things. This is one of those papers where you can pick up a few ideas for analyzing or looking at data or measuring something that you may not have initially thought of. This was certainly the case for me while I read this paper.
There are two effects of additional filtration: reduced patient entrance exposure (from removal of low-energy x-rays) and increased tube loading (from increased technique to compensate for the radiation removed by the additional filtration).
The change in mAs for varying amounts of added filtration and different projections was examined under three conditions: constant patient entrance exposure, constant patient exit exposure and constant film optical density. If I was doing the same study, I probably only would have thought to look at entrance exposure (since it is easiest to measure) or CR exposure index (we use digital systems here).
Maintaining constant entrance exposure required the highest increase in mAs for a given amount of filtration, while maintaining constant film density required the lowest increase. To avoid increasing the amount of image noise with added filtration, I think the ideal parameter to maintain would be constant optical density (or receptor exposure for digital systems). Since maintaining constant optical density is more labour intensive to measure, constant exit exposure is probably and easier parameter to work with (and already measured by phototimer systems). Both methods resulted in similar increases in mAs.
Increased technique also affects image quality due to focal spot blooming when the tube current is increased. However this is normally a very small effect, which was confirmed by the authors. There is also the potential for increased motion blur when exposure time must be increased, but with the constant exit exposure/optical density methods, the increase in exposure time was small enough so that motion was not a problem.
Even with 4.0 mm added filtration, the increase in mAs should be well within the range of x-ray units to accomodate by increasing mA and/or time without adversely affecting image quality.
Overall I thought this was a well done paper that clearly showed that the impact of added filtration was minimal and easily accomodated by most x-ray systems.
Yesterday my server got hit by about 15 attempts to find what I guess to be some kind of buffer overflow vulnerability in my webserver using some kind of HTTP SEARCH method. Never knew there was such a method until now. At first, about the only verifiable reference I could find about it was an old W3C page indicating it was only a proposed method. No mention of it in the HTTP RFC 2616 document at all. Then I found (thanks to Google) a reference in someone's presentation on DAV properties starting here. Seems to be a DAV thing. I only found mention the SEARCH method in a draft document.
The client invokes the SEARCH method to initiate a server-side search. The body of the request defines the query. The server MUST emit an entity matching the [RFC2518] PROPFIND response.The SEARCH method plays the role of transport mechanism for the query and the result set. It does not define the semantics of the query. The type of the query defines the semantics.
Of course now that I know it's a DAV thing, there's plenty of stuff out there about it.
Basically the attack consisted of sending a really long SEARCH request (similar to sending a HEAD/GET/POST request I suppose) containing well over 8K worth of \x90, \xb1, \x02 and probably followed by other things. Apache 2 logs it as "request failed: URI too long (longer than 8190)". I take that as a good sign Apache 2 isn't vulnerable to this kind of attack.
All of the requests came from very different IP addresses which points to some kind of DDoS type of attack.
Always a good idea to keep an eye on the log files. They can tell you a lot about what's going on with your system. One of these days I'll have to make like every other decent sysadmin type out there and set up some scripts that scan the log files and mail me the interesting bits.
Today I get to mess around with our newest cath lab acquisition. Actually I did some initial messing with it doing the acceptance testing earlier this month, but now I get to play and have some geeky medical physicist fun with it.
It's a fairly unique (for the US) system and very cutting edge. As far as I've been told, it's the first system to be installed in the US. A Siemens Axiom Artis with a couple of really large magnets from Stereotaxis used for steering a sepcially designed catheter guide wire through the arteries of the heart.
The x-ray system itself is the first flat panel fluoroscopy unit I've laid my hands on for testing. These things are impressively small and compact. Image quality and performance was ok, but not stunning. Noticed some pixellation getting to the smaller mag modes, but nothing severe.
There are a couple of weeks to go before applications training starts and they put it to clinical use, so this is my last good chance play on it without having to stay after hours. There are a couple of things I plan on checking out.
I'm told the magnets (there are two of them) are 0.7 Tesla permanent magnets, but drop down fairly quickly to about 0.08 Tesla about a meter away. Magnetic fields cause charged particles to move in a circular path, and ion chambers work by measuring ionization in air, so the first thing I was curious about was what kind of an effect the magnets would have on my exposure meters. Further complicating things is that the magnetic field produced by these jammies far from static (which causes much havoc with the angiography unit next door). The magnets articulate and move, which is how the catheter guide is steered. I don't really expect a significant effect, but I don't think it's ever been documented. Maybe I'll even get a short technical note out of it to publish somewhere.
Of course any effect on an ionization chamber while the magnets are articulating is pretty moot, because I don't ever expect to be making exposure measurements while the magnets are being used. But like most physicists, I do things to satisfy my curiosity, and this is definitely one of those things.
If you're interested in some of the latest up and coming goodies for your system, check out Tom's Hardware Guide's coverage of CeBIT in Hanover.
I'd heard about this new 0.85" drive from Toshiba, but I thought it was 0.85" thick. No big deal. Then I saw this, and realized that it was the platters that were 0.85" and have up to 4 GB capacity! Whoa! And I thought IBM Microdrives were small.
I think the Superpower case is particularly cool. And how about those motherboards...ooo yeah, baby...
Drool...
Tomorrow we're off to Charlotte to catch the Verizon Ladies First Tour 2004: Beyonce, Alicia Keys and Missy Elliott concert. My wife wanted to go and I'm just tagging along for the ride. So armed with nothing more than Mapquest directions, a map and some snacks, we're going to hit the road and see how many times we can get lost before getting to our hotel and then the coliseum.
Not quite sure what kind of seats we ended up with. But it seems like with most concerts, no matter what seats you end up with you're staring at a tiny little figure on a giant state really far away. Maybe I'll spend my time doing the Kid's in the Hall "I'm crushing your head" thing.
Ok, I couldn't resist this one
You are Gavin! If your head were made of veal, which you know it is not, but if it were made of veal, how much would it be worth? $20? No, you don't think you'll sell. You are a bit clueless as to what is really going on around you, in fact, you seriously annoy everyone you come in contact with. Although, this does not seem to phase you in the least. As long as you've got your glasses and your backpack and your mom is away getting her makeover done, you're happy, and are content to ask useless questions and give useless answers until the cows come...which they do, every Thursday, right after they lunch with the President.
Which Kids in the Hall Character Are You?
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Just installed the latest Firefox nightly build (20040326) and either I'm on speed or the Firefox guys have made some amazing speed improvements over the last nightly build I installed (from a couple of days ago). Or else I'm just imagining things. But at any rate, it sure seems a lot faster than it did a few minutes ago. Especially rendering pages with tables (one of the things I've always thought Mozilla could do better).
Firefox just keeps getting better and better every day.
Hard to believe, but 5 years ago today, the wife packed me and all our stuff up and moved us from our cozy little apartment in Dearborn Heights MI to another cozy little apartment in Charleston SC. We're still in that cozy little apartment after 5 years and 4 different management companies. It's a good location and a really nice place, so we really haven't been all that motivated to move. We've been thinking about it lately. We're starting to outgrow our cozy little apartment. Once our credit card debt gets paid off, we'll start working on saving for a house. In the meantime, we'll probably stay in our cozy little apartment. It's close to work, close to the peninsula, close to a lot of really good restaurants and shopping, and best of all close to the beach. Can't ask for much more.
The concert over the weekend was ok. Loud, very loud. My ears are still ringing. I'm not really a big fan of rap and hip-hop music, but my wife is, and she listens to it so that means I listen to it too.
We actually ended up with some reasonably decent seats. Halfway up the first tier behind the left corner of the rink, with the stage at about the far blue line. The people on stage were still pretty small, but visible through the crowd.
The concert opened with someone named Tamia who sang pretty well. Next up was Missy Elliot who had a pretty active show, although I couldn't understand a word she was singing/rapping about. Then came Alicia Keys, who I thought was by far the best part of the show. My wife thought so too. Sang well, played some great piano and really played to the crowd. Last up was Beyonce. Made a good entrance, but I thought the performance was lacking. My wife thought she did too much dancing and running about the stage, and not enough singing. And a lot of the time I thought her background instruments and singers drowned out her singing. The rest of the audience seemed excited enough about her though. A surprise appearance by Jay-Z really sent the audience through the roof. I think the crowd got more worked up when he popped up on stage than they did about Beyonce.
And that was the concert. 100+ dB of ear numbing noise, shrieks and drums and probably about 120dB when Jay-Z came out.
The other day while setting up Samba on our RH 9 box, I found out about this very cool sysadmin tool called Webmin. This thing is absolutely amazing. An entirely Perl/web-based application for helping with server sys admin. The primary purpose appears to be to provide a nice usable GUI for configuring and setting up the vast array of server software you will find on a typical server. It's all module based, so there is a module to help you deal with Apache config, setting up Samba and Samba shares, NTP, Sendmail, Procmail and more. All kinds of good stuff. No more wading through config files and trying to remember where the config file for whatever daemon is located.
Of course, you still need to know what you're doing, and not every single configuration option for every daemon or config file is available. This is no substitute for sys admin knowledge. It just places all the config stuff in one easy to access location and provides an easy to use interface. Very sweet indeed. And best of all, it's open source!
Samba is a very cool tool, especially if you have a mix of Windows and *nix servers and clients. But it seems like every time I have to do anything with Samba, it's like pulling hair and teeth to get everything to work properly. On paper, Samba is easy to set up and configure. In real life, I always end up wanting to pitch the Windows box out the window.
You read through the Samba man page, set up smb.conf to do what you want and then go to the Windows box and try to map the share you just set up. Then all you get are message boxes from Windows claiming the username and password are invalid. Or it works fine on one Windows box, but doesn't work on any other ones. Or only one account works, but none of the others. Nothing wrong with what you put into smb.conf. Works just fine on the server with smbclient. Just the stupid Windows boxes refuse to work properly.
Argh.
Update: Ok, finally got things to work nicely. Upgrading to Samba 3.0.2 did the trick. I guess the docs I was using and the Samba version I had installed didn't quite match up. Still want to pitch my Windows box out the window though.
