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I’ve just bught an NVidia video card from Computers and Parts Land (CPL) [1].
I asked for a PCIe*8 card but was assured that a PCIe*16 card would work. However when I got it home I discovered that it would not fit, the size difference was obvious enough that I didn’t even need to unwrap the new card.
According to the Wikipedia page for PCIe (PCI Express) [2] it is quite legal to have a motherboard implement a slower version of PCIe but have the full slot width, so a motherboard could have PCIe*1 implemented but have a socket that will fit a PCIe*16 card. The motherboard and the card will negotiate the capabilities that they both support. But there is no requirement to have a larger socket than required to use the capabilities of the motherboard.
The CPL salesman assured me that any PCIe*16 card will fit into any PCIe*8 socket. I presume that he is used to white-box gear manufactured by companies that can save a few cents on the sockets if they make them all the same size. The Dell PowerEdge T105 that I own has PCIe*8 sockets that do not fit PCIe*16 cards.
So now I have to return the card, and the CPL web site doesn’t even give the hours that the store is open, so I have to call them. Sigh.
Update: I returned the video card, first I had a debate with the CPL guy who had sold it to me regarding whether such PCIe sockets exist. He suggested that I had mistaken a PCI slot for a PCIe slot and was not convinced until I showed him a picture I had on my phone. He then claimed that Dell made sub-standard machines for not using a PCIe*16 socket for PCIe*8 connectors – so it was Dell’s fault not his fault for delivering me a PCIe*16 board when I asked for a PCIe*8. He told me that no-one had ever made a PCIe*8 video card. Then he told me that I was lucky to not have a re-stocking fee (they sold me a device that was not what I asked for, I returned it in perfect condition on the same day and I was lucky to not pay them for the privilege). They gave me a credit note for the value of it (not a refund).
I recommend never doing business with CPL if you can avoid it. I will make exactly one more purchase from them, that will be to use the credit note.
Bruce Schneier has written about the foolish actions of Justice Antonin Scalia [1]. Antonin made some comments opposing the need for greater privacy protection, most people could get away with doing that, but when a Supreme Court Justice does so it gets some attention. In response to this Fordham University law professor Joel Reidenberg assigned his class a project to discover private information on Antonin using public sources. The class produced a dossier of such information which was then offered to Antonin [2], but which was not published.
Now anyone who knows anything about how the world works would just accept this. Among other things Antonin now knows what is publicly available and can take steps to remove some public data according to his own desires. But being apparently unaware of the Streisand effect [3] Antonin went on to say the following:
It is not a rare phenomenon that what is legal may also be quite irresponsible. That appears in the First Amendment context all the time. What can be said often should not be said. Prof. Reidenberg’s exercise is an example of perfectly legal, abominably poor judgment. Since he was not teaching a course in judgment, I presume he felt no responsibility to display any.
This is of course essentially issuing a challenge to the entire Internet to discover the information that the Fordham students discovered. Of course doing so would not be fun unless it was published. The meme of 2009 has yet to be defined, it might be discovering and widely publishing personal information about Antonin.
Already one of the comments in Bruce Schneier’s blog suggests that activists should do such research on all senior figures in the US government to encourage them to take privacy more seriously. I expect that the first reaction of the legislative branch to such practices would be to enact special laws to protect their own privacy while still allowing large corporations (the organisations that pay for the election campaigns) to do whatever they want to ordinary people.
It’s an interesting situation, I predict that Antonin will regard this as one of the biggest mistakes he’s ever made. I’m sure that there are many more LULZ to come from this.
It’s generally accepted that certain things need redundancy. RAID is generally regarded as essential for every server except for the corner case of compute clusters where a few nodes can go offline without affecting the results (EG the Google servers). Having redundant network cables with some sort of failover system between big switches is regarded as a good idea, and multiple links to the Internet is regarded as essential for every serious data-center and is gaining increasing acceptance in major corporate offices.
Determining whether you need redundancy for a particular part of the infrastructure is done on the basis of the cost of the redundant device (in terms of hardware and staff costs related to installing it), the cost of not having it available, and the extent to which the expected down-time will be reduced by having some redundancy.
It’s also regarded as a good idea to have more than one person with the knowledge of how to run the servers, jokes are often made about what might happen if a critical person “fell under a bus“, but more mundane things such as the desire to take an occasional holiday or a broken mobile phone can require a backup person.
One thing that doesn’t seem to get any attention is redundancy in the machine used for system administration. I’ve been using an EeePC [1] for supporting my clients, and it’s been working really well for me. Unfortunately I have misplaced the power supply. So I need to replace the machine (if only for the time taken to find the PSU). I have some old Toshiba Satellite laptops, they are quite light by laptop standards (but still heavier than the EeePC) and they only have 64M of RAM. But as a mobile SSH client they will do well. So my next task is to set up a Satellite as a backup machine for my network support work.
It seems that this problem is fairly widespread. I’ve worked in a few companies with reasonably large sysadmin teams. The best managed one had a support laptop that was assigned to the person who was on-call outside business hours. That laptop was not backed up (to the best of my knowledge, it was never connected to the corporate LAN so it seems that no-one had an opportunity to do so) and there was no second machine.
One thing I have been wondering is what happens to laptops with broken screens when the repair price exceeds the replacement cost. I wouldn’t mind buying an EeePC with a broken screen if it comes with a functional PSU, I could use it as a portable server.
I was doing some routine sysadmin work for a client when I had to read mail in the system administration mailbox. This mailbox is used for cron job email, communication with ISPs that run servers for the company, and other important things. I noticed that the account was subscribed to some mailing lists related to system administration, the following is from one of the monthly messages from a list server:
Passwords for sysadmin@example.com:
List Password // URL
---- --------
whatever-users@example.org victoria3
That doesn’t seem terribly exciting, unless you know that the password used for the list server happens to be the same as the one used for POP and IMAP access to the account in question, and that it is available as webmail… Of course I didn’t put the real password in my blog post, I replaced it with something conceptually similar and equally difficult to guess (naturally I’ve changed the password). The fact that the password wasn’t a string of 8 semi-random letters and digits is not a good thing, but not really bad on it’s own. It’s only when the password gets used for 3rd party servers that you have a real problem.
I wonder how many list servers are run by unethical people who use the passwords to gain access to email accounts, and how many hostile parties use such lists of email addresses and passwords when they compromise servers that run mailing lists.
Now there would be an obvious security benefit to not having the list server store the password in clear-text or at least not send it out every month. Of course the down-side to doing that is that it doesn’t give someone like me the opportunity to discover the problem and change the password.
The people who made the above magazine advert gave it two top-halves to the burger bun. But I think that there is actually a demand for such buns, and that it is possible to make them!
Traditional buns have a flat bottom where they rest on a baking tray. One solution to this problem would be to bake in outer space, another possible solution would be to develop a rapid baking process that allows baking in a free-fall aeroplane, but both of these would be unreasonably expensive.
It seems that it would be viable to bake double-ended buns by having a rapidly rising column of hot air to suspend the bun. The terminal velocity of a bun would probably not be that high (maybe 60Km/h) and it should be quite easy to have a pipe full of hot air that bakes the buns. As slight variations in the density and shape of the bun would affect the air-flow it would be necessary to closely monitor the process and adjust the air speed to keep the bun afloat. Manufacturing cheap ovens that use LASERs to monitor the position of the bun should not be difficult.
This might blow the sesame seeds off the bun, but this problem may also be solvable through careful design of the bun shape to make it less aerodynamic and by strongly attaching the seeds. I’m not sure how you would do this.
P. W. Singer gave an interesting TED talk about the use of robots in war [1]. He briefly covered some of the ethical and social issues related to robot soldiers as well as showing many pictures of existing robots.
Since November 2007 there has been a request for Google Gears to support “Iceweasel” (the Debian name for Firefox due to trademark issues)[2]. Apparently supporting this different name is not easy for the Google people. If you visit the Google Gears Terms and Conditions page [3] then it will work with Iceweasel on the i386 platform – but not for AMD64 (or at least not my Debian/Lenny AMD64 system).
Charles Moore gave a disturbing TED talk about the “Great Pacific Garbage Patch” [4]. Pollution in the oceans from waste plastic is worse than I realised.
Ressuka documented how to solve the Time went backwards problem on Xen DomUs [5]. Run “echo “jiffies”> /sys/devices/system/clocksource/clocksource0/current_clocksource” or use “clocksource=jiffies” in your DomU kernel boot parameter list.
Nassim Taleb [6] has written Ten principles for a Black Swan-proof world [7], this is in regard to the current US financial crisis. It’s worth noting that he made a significant amount of money due to successfully predicting some aspects of the crisis.
James Duncan Davidson has some good advice for speakers based on his experience in filming presentations [8]. Some of the ones that were not obvious to me were:
Take off your name-tag – it doesn’t look good
Stay in the part of the stage with the best light
Almost two years ago I blogged about a strange performance problem with SATA disks [1]. The problem was that certain regions of a disk gave poor linear read performance on some machines, but performed well on machines which appeared to be identical. I discovered what the problem was shortly after that but was prevented from disclosing the solution due to an SGI NDA. The fact that SGI now no longer exists as a separate company decreases my obligations under the NDA. The fact that the sysadmins of the University of Toronto published all the most important data entirely removes my obligations in this regard [2].
In their Wiki they write “after SGI installed rubber grommits around the 5 or 6 tiny fans in the xe210 nodes, the read and write plots now look like” and then some graphs showing good disk performance appear.
The problem was that a certain brand and model of disk was particularly sensitive to vibrations. When that model of disk was installed in some machines then the vibrations would interfere with disk reads. It seems that there was some sort of harmonic frequency between the vibration of the disk and that of the cooling fans which explains why some sections of the disk were read slowly and some gave normal performance (my previous post has the graphs which show a pattern). Some other servers of the same make and model didn’t have that problem, so it seemed that some slight manufacturing differences in the machines determined whether the vibration would affect the disk performance.
One thing that I’ve been meaning to do is to test the performance of disks while being vibrated. I was thinking of getting a large bass speaker, a powerful amplifier, and using the sound hardware in a PC to produce a range of frequencies. Then having the hard disk securely attached to a piece of plywood which would be in front of the speaker. But as I haven’t had time to do this over the last couple of years it seems unlikely that I will do it any time soon. Hopefully this blog post will inspire someone to do such tests. One thing to note if you want to do this is that it’s quite likely to damage the speaker, powerful bass sounds that are sustained can melt parts of the coil in a speaker. So buy a speaker second-hand.
If someone in my region (Melbourne) wants to try this then I can donate some old IDE disks. I can offer advice on how to run the tests for anyone who is interested.
Also it’s worth considering that systems which make less noise might deliver better performance.
While shopping at Highpoint [1] today I noticed that they had a new loyalty system. It’s called Mo Rewards [2] (for which the real web site is at MoCoMedia.net [3] which has no link from the main site because they didn’t care enough about their web presence).
The way that Mo works is that everyone gets a free RFID token similar to the two in the above photograph. The token comes with a pseudo-random seven letter code that you have to SMS to register it to your phone. You SMS the code and then receive a confirmation SMS. After that you can wave your token near a detector any time you visit the shopping center and you will receive three SMS messages with discount offers. You can send an SMS with your gender and birth-year to receive more targeted offers. To redeem offers you have to wave your token near a detector at the store so they know who is using the offers.
Then of course once the database knows that you are a regular customer at a certain shop they can send you targeted advertising to entice you to buy from that shop on every visit. I presume that they have some sort of bidding system for adverts from the shops of a similar nature to the Google advertising.
It’s an interesting system and a lot better than most loyalty programs.
One interesting thing about this is that high quality RFID devices are being given out for free. The tokens are quite solidly constructed and could be used for a variety of other purposes. I couldn’t find anyone offering RFID tags at a reasonable price with a quick Google search (the cheapest was $75 for 100 tags – and they were the fragile ones used for marking stock in shops). So a hobbyist who wanted to do some RFID stuff could buy a cheap reader under one of the demo offers (where you get a reader and a small quantity of keys for a reasonable price) and then collect free RFID tokens from shopping centers. I expect that the number of people who would do such things is small enough to not be statistically significant and therefore not affect the business model. The tags are given out freely with no requirement that you must use them for the expected purpose (Mo Rewards) instead of using them for your own RFID work.
My SE Linux Play Machine [1] has a file named thanks.txt for users to send messages to me [2].
On a number of occasions people have offered to give me things in exchange for the password for the bofh account (the one with sysadm_r privileges). I’ve been offered stolen credit cards, a ponzi scheme of root access to servers on the net, and various other stuff. Today I received an amusing joke entry:
Hello Kind Sir,
I am Dr. Adamu Salaam, the the bank manager of bank of africa (BOA) Burkina Faso West
I am sending you this message about the $3.14159 million dollars in bank account number 2718281828450945. I will give you this money in exchange for the password to the ‘bofh’ account.
The amount of money is based on the value of Pi. The account number is based on the mathematical constant e [3].
It’s a pity that the author of that one didn’t sign their real name. Whoever created that should have claimed credit for their work.
TED published an interesting interview with Shai Agassi about electric cars [1]. One idea that I hadn’t heard before is that of moving car batteries between regions as they lose capacity. An old battery for an electric car that can only handle short journeys may be useful in a region where journeys are typically short. On a similar note I expect that in a few decades the less prosperous countries will import old electric vehicles and fit them with 4 or more batteries. Last time I checked the Prius battery pack weighed about 120Kg, so the car would be usable with 4 battery packs if driven at low speeds.
Shai Agassi also gave a TED talk on this topic [2]. The real solution for the problem of providing convenient and affordable electric vehicles is to start by recharging the batteries whenever the vehicle is parked (at the office, shopping center, home, etc). Then on the rare occasions when the car is being driven for longer distances and the battery gets flat it can be swapped for a charged battery. They have apparently designed a robot for changing car batteries, so changing the battery would be like driving through a car-wash. He describes this as an economic model that decouples the expensive battery from the car, so you pay for the use of the battery not the ownership – just as with a petrol car you pay for the petrol you use not for a portion of the ownership of an oil well.
He also pointed out that cars produce 25% of the world’s CO2 emissions, so his plan for all electric cars everywhere seems to be an essential part of solving the environmental problems. He then compared this to the UK parliamentary discussion on ending slavery, at the time slaves provided 25% of the energy used by the UK. After a month of discussion the decision was made to make the moral choice and end slavery regardless of the cost.
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