features of BMW 5 and 7 series

March 7, 2007 | etbe

I was reading the brochure about the BMW 530i Touring (which seems to be the BMW name for what is known as a “Station Wagon” in Australia or an “Estate” in Europe). I looked at the brochure on the “Touring” because I am interested in a Station-Wagon – the Sedan version of the 5 series is almost the same in every way other than size and shape.

Here are some of the interesting features:
Adaptive headlights, they turn in to a corner when the car is cornering (showing where you are about to go instead of showing you the scenery off the road) and the high-beam switches off when an oncoming vehicle is detected.

Head-up display for speed, navigation, and other driver-relevant information.

Park distance control (PDC). Gives audio and visual alerts when you are about to hit something at low speed.

Eight air-bags of which only the necessary ones will inflate in a collision, and the inflation power will be determined by the severity of the collision.

Dynamic stability control (DSC), traction control, corner brake control, and more. Described as “all of the known features of DSC”.

Seat-belt pre-tensioners in the rear and pyro-technic tensioners for front seat belts.

Rain sensor that turns on headlights, and optional head-light washers.

According to it’s brochure the 7 series has bumpers that regenerate their original shape in collisions of speeds up to 6Km/h and a tire defect indicator. Apart from that there doesn’t appear to be much benefit over the 5 series apart from more luxury features.

To get the PDF files from BMW Australia (without following my links which BMW will probably break soon) you have to fill in a form with “contact details”. To enter that form you need a browser that works with their javascript (which means not Konqueror) so that you can enter your postcode and be prompted with a list of suburbs that match the post-code. The second-last page of that process allows you to download PDF files and it seems to indicate that your data will not be stored if you don’t continue past the stage where you download the PDF files. It would be good if BMW could get smart and make their PDF files as easy to download as Mercedes does.

In terms of safety features it seems that the 7 series offers little over the 5 series. By comparing the brochures it seems to me that the Mercedes S series (as described in my previous blog post) has many more safety features than any BMW. Assuming that the BMW documents are accurate they don’t seem to compare well with the Mercedes S class. From a quick search on drive.com.au (the best web site for buying used cars in Australia) it seems that the Mercedes keeps it’s value better than the BMW – other people apparently share my opinion of the relative merits of the cars.

In future posts I’ll summarise the features of some other cars that I consider interesting.

presentations and background color

March 5, 2007 | etbe

In response to my last post about using laptops for presentations it has been suggested to me that using white (or a very bright color) as the background color can help some displays synchronise with the signal. I haven’t had an opportunity to test this but it seems likely that as most computers are configured with a white background nowadays the display hardware is optimised for this case.

Another benefit of a light background is that it provides more ambient lighting to the room where the presentation is held. If all the lights are turned off (sometimes there is no dimmer switch) then the radiant light from the screen is the only form of illumination for the room.

Finally with the way the current generation of beamers work there is less heat trapped in the beamer if there is mostly white on the screen. This will hopefully decrease the incidence of hardware failures during lectures (which unfortunately are not uncommon in my observation).

Update:

Based on a comment on this blog entry I did a quick survey of the color scemes, black on white, yellow on blue, and white on green. Black on white got the most votes with some people saying that yellow on blue was most aesthetic while black on white was easiest to read (“clear and boring” was one comment).

One person pointed out that the light diverges slightly so black on white makes the letters look smaller while white on black makes them look bigger. My response to this is to use a slightly larger font.

meeting people at Linux conferences

March 3, 2007 | etbe

One thing that has always surprised me is how few people talk to speakers after they have finished their lecture. A lecture might have many questions and the questions may be cut off, but when the speaker leaves the room they will usually do so alone.

When I give lectures at conferences I’m always happy to spend more time talking to people who are interested in the topic and disappointed that so few people choose to do so. It seems that other people have similar experiences, there have been several occasions when I have invited speakers to join me for lunch and no-one else has shown interest in joining us.

Usually the most significant factor in making someone offer a talk at a Linux conference is the opportunity to teach other people about the technology that they are working on. People with that motivation will take the opportunity to teach people at lunch, dinner, whenever.

Linux Conf Au has an event called the “Professional Delegates Networking Session” which is regarded by some people as the way to meet speakers (about half the delegates don’t attend so the ratio of speakers to delegates is significantly better than at other conference events). But it seems to me that it’s more efficient to just offer to buy them dinner. When I worked for Red Hat the maximum value for a gift I could accept was $100US, I expect that Red Hat has not changed this policy since then and that most companies that employ speakers at Linux conferences have similar policies. $100US is more than a meal costs at most restaurants that are near a Linux conference.

If I was a manager at a company that sent employees to a Linux conference I would first send email to some speakers who were working in areas of Linux development that were related to the projects that the employees were working on. I would ask the speakers if they would be interested in having dinner bought for them by my company and give them the option of bringing one or two friends along for a free meal (the friends would probably be people who work in similar areas).

spare tires

March 2, 2007 | etbe

The following letter was published in the RACV Magazine. The Royal Automobile Club of Victoria is a driver advocacy organization that provides roadside assistance and insurance. The fact that they published my letter means that the idea can’t be totally wacky so I’ll blog it. ;)

There have been many mentions recently in RoyalAuto about space-saver spare tires. Some manufacturers claim that they are to save weight which seems to be a benefit for the driver.

I wonder if most drivers really need a spare tire. For my own driving I only have a flat tire about every second year and I almost never drive outside the metropolitan area. Given how rarely I call for road-side assistance I think I would be better off without a spare tire and with the option of having the RACV deliver one for me if I needed it.

I expect that the time taken to deliver a spare tire would be greater than that required for a regular road-side assistance call, and that it might count for more than a regular assistance call, but given that the cheapest roadside assistance package has 8 calls a year I expect that most years I would still use less than half my quota of calls.

Not having a spare tire would save some weight (and therefore fuel) and would provide a little extra cargo space.

Also it seems to me that small cars are unlikely to ever be driven outside the area that is serviced by the RACV and similar organizations. For a small car the lack of a spare tire in the car design would offer a significant improvement to cargo capacity. If the RACV and other organizations endorsed and supported cars without spare tires then the car manufacturers could design small vehicles with more cargo capacity and less fuel use.

Mercedes S class and car safety

March 1, 2007 | etbe

The S Class Mercedes has some really interesting safety features, see this 6.8M PDF file for details. If you are interested in technology then you want to read it just to learn about all the cool features – it’s got more technology than a Prius!

The S class includes the following features to protect the occupants in the event of a crash:

Tire pressure monitors
Electronic Stability Program (ESP) to selectively apply the brakes to reduce the risk of skidding
Active suspension
Pre-Safe is a management feature that recognises a potential collision by the steering and braking patterns of the driver and prepares the vehicle for an impact. This can involve adjusting the sun-roof, the seat-belts, and the driver’s seat position to prepare for impact, closing the side windows, and inflating air chambers in the sides of the seats.
Head rests that automatically adjust in the event of a rear impact

The following features reduce the risk and/or severity of a crash:

Night view (infra-red) display gives a display of potential obstacles ahead without dazzling oncoming traffic
Distronic Plus is a brake assistance package that includes automatic braking based on radar surveillance of the traffic ahead
4Matic is a new feature that combines AWD with the traction-control feature that has become common on all expensive cars. This means that when any combination of wheels starts to spin on water or ice the brakes will be applied to them so that the wheels that have good grip can still be used for acceleration.

After a crash there are more safety features that can help you:

The engine can be automatically turned off after an impact and if necessary the fuel supply can also be cut
The hazard lights and emergency interior lights can be automatically activated
The side windows can be partially lowered, if your car lands in water deep enough to submerge it then you MUST open the windows as soon as possible – otherwise water pressure may make it impossible to open the doors – people forget this so it’s good to have an automatic feature
Automatic door unlocking after an impact (good for rescuing unconscious occupants)
Cutting points marked on the windscreen and rear window for the benefit of emergency workers who need to cut the roof off with the “jaws of life”

These features are documented as being available in the latest S Class, I haven’t investigated what is available in the cheaper models and I’m not even sure where to find information on the safety features available in older models (a second-hand E class is more in my price range). But if I won the lottery a S class Merc would be high on my list of things to buy!

If you know of other cars that have a similar set of safety features to the S class and cost less then please let me know.

I will probably write a blog post about the BMW safety features in the near future. I couldn’t do so immediately because the BMW web site sucks. They have a form for me to fill in contact details so that they can post me a brochure (I want to read it NOW ONLINE). The form doesn’t like my postcode and refuses to proceed (it should at least have an option for them to contact me via email or phone).

a good dog for uplifting

February 15, 2007 | etbe

The Norwegian Puffin Dog has six toes that are all fully formed. This has to be a good start for the uplift process.

The requirements for uplift are intelligence, speech, and the ability to use tools (dexterity in fingers). It seems that the Puffin Dog has a finger advantage over other breeds. Also the Lundehund has the ability to spread it’s front legs out horizontally and to turn it’s head around to face backwards, both these abilities significantly increase it’s potential ability at using tools (uplifted dogs could use their mouths to manipulate tools as well as their hands).

So we need to find a breed that has good vocal capabilities and a breed that is intelligent and produce a cross-breed that has the best of all three!

Lundehund Syndrome sounds nasty, and would be almost impossible to breed out of pure bred dogs, but when producing a cross-breed it should be easy enough to do. Given that we don’t care whether the uplifted dogs look like Lundehund’s, have the same number of teeth, or are identifiable with that breed in any way other than dexterity it should be easy to breed out the genetic damage.

execmod

February 10, 2007 | etbe

Ulrich Drepper has written a good web page about text relocation which is most often noticed as execmod failures reported when running SE Linux. When an AVC message reports a failure of execmod against a shared object it means that the object has text relocations (the shared object code writes to code that it executes to fix up addresses). This is due to being compiled without -fPIC or -fpic.

The command eu-findtextrel (from the elfutils package) when run with a parameter of the shared object in question will tell you which functions were compiled without -fpic or -fPIC.

The module in question must be recompiled with -fpic or -fPIC to generate the correct code.

Without SE Linux it’s still a bug to compile a shared object without position independent code, so any shared object which can’t run under SE Linux because of execmod will probably have problems in other situations anyway (maybe only on certain architectures).

xen and yoyo

February 9, 2007 | etbe

One of the benefits of Xen is that it allows a machine to be easily rebooted. Remote console and remote power management technologies are either expensive or implemented on the motherboards of expensive machines. With Xen the virtual machines can be managed without such expense and also with less effort.

This raises immediate possibilities for training sys-admins. One problem with training system administrators is that they need to have servers to administer and the mentor needs to be able to easily access them and fix them when they become unbootable. Xen makes these problems easy to solve on cheap hardware.

Monash University has for many years had a machine named Yoyo which is used for training sys-admins. It’s not expected to be up as much as machines that are run by experienced sys-admins (hence the name) but I expect it would still have better uptime than a lot of corporate servers.

Unfortunately until recently there were no options available to people who weren’t Monash students for learning about system administration. To solve this I want to run some sys-admin training with a server.

My plan is to set up a machine running Xen at a server room and provide a basic Debian install in a domU. I will then give the root password to a small group of trustworthy people (who I have known for some time or who are local and can be verified) and start the training. My plan is to set up a mailing list for emergency communication on one of my servers and have the trainees set one up for regular use on the domU. I will provide DNS secondary service and have an NS record for yoyo.coker.com.au point at the machine in question so the first task for them would be to run a DNS server.

I won’t have unlimited bandwidth so I will track the bandwidth use from the dom0, and I will use the dom0 to make backups of the system via LVM snapshots.

The terms of service etc will be mostly copied from the Monash machine.

Please let me know if you have any suggestions for how to run this.

Hopefully this will work out and other people will want to do the same. If you run such a machine then please add a comment to this post with the URL for information on it.

presentation laptops

January 25, 2007 | etbe

I suggested in a previous blog entry that conferences should provide computers that speakers can use for their presentations. The reason for this is that getting one computer working with the beamer in each room is an easy task, while getting the laptop of every speaker to work is much more difficult.

It seems that my idea has been rejected by almost everyone who read it, so I’ll document some tips for getting a laptop working.

 SZ:    Pixels          Physical       Refresh
*0   1400 x 1050   ( 474mm x 356mm )  *50
4    640 x 480    ( 474mm x 356mm )   50
5    800 x 600    ( 474mm x 356mm )   50
6   1024 x 768    ( 474mm x 356mm )   50
8   1280 x 960    ( 474mm x 356mm )   50
9   1280 x 1024   ( 474mm x 356mm )   50

Firstly there is the command xrandr which can be used to change the resolution without logging out. Above are the most useful lines produced by running xrandr with no options on my Thinkpad T41p. The left column is the index to the list of resolutions. For example I run xrandr -s 9 to use mode 1280×1024 and xrandr -s 0 to use mode 1400×1050. This takes much less time than editing an X config file!

The next thing to note is that my Thinkpad has a refresh rate of 50Hz, apparently most beamers expect at least 60Hz, this explains why I have had ongoing problems in getting my Thinkpad to correctly work for presentations for the entire time that I have owned it. If you own such a Thinkpad then I recommend that you just bring another laptop to do your presentation on the assumption that the display possibly won’t work and probably won’t work properly! I had developed this habit anyway after repeated problems in getting my Thinkpad working (occurring on a number of occasions in several countries). It’s good to now know the reason for this (thanks Keith).

When setting the resolution there are often tweaks that can be used. For example in my talk for the Debian Miniconf of LCA 2007 I used mode 800×600 (I think – Keith set it up and I didn’t look closely after verifying that things basically worked). Even though the beamer didn’t have good support for a low refresh rate it worked when the resolution was low enough. Fortunately the xrandr program allows changing resolution fast enough that all 13 resolutions could be attempted in about a minute.

The support for better display detection and configuration is steadily improving. Hopefully this year the problems will be solved (which means that for the Debian and RHEL releases in 2008 the problem will be solved).

A possible work-around is to use Xephyr (the replacement for Xnest). In a previous blog entry I described how to get Xephyr going for use by Xen images. It seems to be a common symptom of display synchronization problems that the edges of the screen will be clipped. The most common work-around for this is to not use the full-screen mode of OpenOffice – which means that instead of having a small amount of text clipped there is a large amount of OpenOffice menus etc on the screen. As Xephyr accepts any resolution it should not be difficult to arrange for it to use 98% of the screen space and then run the presentation full-screen in the Xephyr window. This will be particularly useful for programs such as MagicPoint (my favorite presentation program) which don’t support a windowed mode of operation.

If you have any other suggestions on how to solve or work around display problems with laptops then please leave comments.

university degrees

January 24, 2007 | etbe

Recently someone asked me for advice on what they can do to improve their career without getting a degree.

I have performed a quick poll of some people I know and found that for experienced people there seems to be little need for a degree. People who have extensive experience but no degree report no problems in finding work, and employers don’t report any reluctance to hire someone who has the skills but no degree.

One thing that a degree is very good for is making a career jump. This is most notable when you get your first professional job, school results and references from part-time work don’t help and a degree is a massive benefit. But if you have proven your abilities in the field then most employers will be more interested in checking references and the interview process than in qualifications. If you are only interested in getting a job that is one level above where you are at the moment then lacking a degree should not be a problem.

Another possibility for someone who lacks a degree is certification such as the Linux Professional Institute (LPI) provides and the Red Hat Certified Engineer (RHCE). One advantage of the RHCE certification is that it is based on fixing misconfigured Linux systems, no theoretical questions, just the type of work that real sys-admins do for their job – this means that people who do badly in traditional exams can be expected to do well, and it also means that the RHCE certification accurately depicts real skills in fixing problems (and it should therefore be more valuable to employers). The LPI exams can be taken by anyone, but to sit for an RHCE you have to be sponsored by an employer.

There are ways of getting career benefits without strictly going upwards. One way of doing this is to move to a region where the pay scales are different. Some years ago I moved from Melbourne, Australia to London to increase my salary. When in London I did work that was a lot less challenging and was paid considerably better for doing so. One thing I discovered is that in London Australians were widely admired for working really hard, I don’t think that Australians work harder than British people on average, but people who will move to the other side of the world to advance their career are generally prepared to work hard!

If you spend some time working in another region and then decide to return home you will probably find that employers are more interested in hiring you for what you have learned in another region. Whether you actually learn things that are of value to potential employers when working in another country is debatable, it probably depends on the individual. But when applying for a job you want to make the most of every opportunity that is available – if someone wants to hire you for the special skills you learned in another country then that’s OK. ;)

Another possibility is moving to a different industry sector. Some industries have career bottlenecks at different levels. If there is no possibility of moving upwards in the area where you work then getting a job with the same skill requirements in a different industry might open up more opportunities. An example of this is working as a sys-admin in a medium sized company that is not IT based. If you are the only sys-admin in the company then there is no possibility of promotion, moving from such a company to an ISP (or other IT based company) would then give the possibility of becoming a senior sys-admin, team leader, or even the manager of the ops team (if management is your thing).

A final option that few people consider is becoming a contractor. Contractors tend to earn significantly more than permanent employees when they do the same work (so becoming a contractor provides a significant immediate benefit) and as the duration of contracts is usually small there is less attention paid to degrees etc (what does it matter if the contractor will only be there for three months?). Of course most contracts last significantly longer than the initial term, some contractors end up working in the same position for 10 years or more!

There are some down-sides to being a contractor, one is that they get less interesting work (offering someone a choice of projects if they become a permanent employee or the project that is deemed to be least interesting if they insist on being a contractor is not uncommon). Another down-side to being a contractor is the way that contractors are used. The ideal way of running a company is to have mostly permanent employees and to use contractors for special skills, short-term projects, and for emergencies when they can’t hire permanent employees. When a company has almost no permanent employees it usually means that something is going badly wrong. This means that if you select a random contract role there is a good chance that it will be one where things are going badly wrong. The money from contracting is good, but it can be depressing when projects fail.

etbe – Russell Coker

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