Older blog entries for etbe (starting at number 1128)

Expectations of Skill and Time

On many occasions I’ve seen discussions about the background knowledge that people are expected to have to contribute to FOSS projects. Often the background knowledge is quite different from the core skills related to their contributions (EG documentation mark-up skills required for coding work or knowledge of code required for writing documentation). One argument in favor of requiring such skills is of the form “anyone who’s good at one aspect of the project can learn skills for the other areas”. Another is of the form “anyone who has time to contribute in one area has time to learn all the other areas, anyone who doesn’t want to learn is being lazy”.

I think it’s reasonable that someone who is considering donating their time to a project would want to start doing something productive immediately. If someone has to spend many hours learning how things work before contributing anything of value they may decide that it’s not a good use of their time – or just not fun. Also if the project is structured to require a lot of background knowledge then that will increase the amount of time that long-term contributors spend teaching newbies which is another way of sucking productive energy out of a project.

I don’t think it’s lazy to want to avoid learning unusual tools before starting a project. Firstly there is the issue of wanting to make productive use of your time. If you have a day for FOSS contributions and you can choose between spending 6 hours learning an environment for one project or 1 hour for another project then there’s a choice of 2 hours or 7 hours of productive work. Someone who has the luxury of being able to spend several days a month on FOSS projects might think it’s lazy to want to make effective use of 1 day, but there are a lot of people out there who are really busy and can only spend a few days a YEAR contributing, spending half a day learning an obscure development environment or documentation system can take a significant amount of someone’s yearly time for such work. To make things even worse some of the best programmers are the ones who have little free time.

For documentation MediaWiki (the software behind Wikipedia and Wikia.com) has a lot going for it. While it’s arguable that it’s not the best Wiki software out there (many people have wanted to argue this with me even though I don’t care) it’s obvious that MediaWiki is the most widely used Wiki software. If you have documentation stored in MediaWiki then most people who have any exposure to the IT industry, the FOSS community, or the Internet in general will already have experience using it. Also Wikipedia serves as a large example of what can be done with MediaWiki, there have been more than a few occasions when I have looked at Wikipedia for examples of how to layout text. Some people might think I’m lazy for never reading the MediaWiki documentation, but again I’ve got lots of other things to do and don’t want to spend a lot of time learning about MediaWiki instead of doing more useful things like creating content.

Project source code should be as consistent as possible. While large projects may have lots of modules and dependencies it’s best to try and keep them all in one place. If your project depends on libraries of code from other sources then it’s helpful to distribute copies of those libraries from the same location as the project source – particularly when the project depends on development versions of libraries. Then if there’s any mismatch between versions of libraries it will be a clear unambiguous bug that can be reported or fixed instead of being an issue that requires checks of what versions everyone is using.

One thing we should aim for in FOSS projects is to get the “long tail” of contributions. If someone spends a day fixing bugs in a dozen projects to get their own system working as desired then it would be good if they could submit patches without excessive effort at the same time.

This doesn’t just apply to FOSS development, it also applies to a large extent to any collaborative project on the Internet. For example if I was to start a Wiki for fans of a sci-fi series wikia would be the first option I’d consider because most potential contributors know it.

Proprietary Software Development

I’ve seen all the same problems when developing proprietary software. The difference is that money and morale is wasted instead of contributions. Often in commercial projects managers choose products that have a good feature list without considering whether all their staff need to be retrained. Programmers can usually train themselves so it’s often a hidden cost, the training is paid for in lost development time (both directly in time spent learning and indirectly when people make mistakes).

One significant advantage of using free software on Windows is that programmers can play with it on their own. For example I’ve never done a fresh installation of SourceSafe or ClearCase, but if I was going to work on a project that involved Git or Subversion on Windows then I could play with it and learn without risking disruption to the rest of the team. If commercial software is to be used then being common and relatively cheap is a significant advantage. MS SourceSafe offers significant benefits over most version control software on Windows simply because the vast majority of Windows developers have already used it and because it’s cheap and easy to setup a test instance if necessary.

I don’t care about the success or failure of proprietary software projects in general (I only care when I’m paid to care). I also don’t expect that people read my blog with the aim of getting advice on running successful proprietary software development projects. This section is merely to illustrate the general nature of such wasted effort on collaborative projects – and I should put my observations of failing proprietary software development projects to use.

Debian

Some Debian Developers are having a discussion about such things at the moment. That discussion inspired me to write this post. But I’m mostly writing about my experience over the course of 20+ years working in the IT industry and contributing to FOSS projects – not in a direct response to the Debian discussion (most of which I haven’t yet read).

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Syndicated 2014-06-20 10:30:24 from etbe - Russell Coker

Phone Car Accessories

Tree Frog Dashboard Mat

phone stuck to fridge

I’ve been given some more MobileZap products to review. The first is the Tree Frog anti-slip dashboard mat [1]. This is designed to allow a phone to stick to an angled surface of the inside of the car without slipping. The pictures on the web site show a phone stuck to a curved angular surface of a car dash. To test this I stuck my phone to my fridge, the flat metal surface of the fridge and the almost flat plastic surface of the gel case of my phone are pretty much ideal surfaces for the sticky mat to adhere to. But even so keeping my phone stuck to a vertical surface is impressive. This mat is cheap enough that it could be used for many other tasks than securing a phone in a car, for example it could be used to stick a phone to the wall of your office. It’s apparently washable and can be expected to keep gripping things if washed regularly.

One thing that could be improved in the mat would be to have some holes in it. When I detached my phone from the fridge some large air bubbles developed between the mat and the fridge, this would be a problem if I wanted to regularly stick my phone to a flat surface such as an office wall.

When in my car it didn’t work nearly as well. The pattern on the surface of the car dash which is designed to avoid glare when driving is difficult to stick to, it’s a bit like trying to attach sticky-tape to unpainted wood for similar reasons. A phone will still remain in place on a 30 degree angle from the horizontal (which is significant) but the mat grips much more tightly to the phone than the dash, which is a little inconvenient as the mat stays attached to the phone when you remove it from the dash.

Sorry for the boring picture, it’s black and flat so there’s not much scope for making it interesting.

3.1A USB Car Charger

AA battery charger and 3.1A car charger

Above is a picture of a 3.1A USB car charger and a AA battery charger. The car charger isn’t particularly exciting, but providing 3.1A through two USB sockets is noteworthy – it can charge one device at 2.1A (the maximum any device draws) or two devices for a total of up to 3.1A [2] (with protection against over-current). Previously in my car I used the 2.1A charger that shipped with my Galaxy Note 2 and an inverter to provide 240VAC as the devices I had to charge a phone from a car socket didn’t provide enough current. This new device uses less space and also allows charging two phones at once. One problem with this device was finding USB cables that could handle the current, for benchmarking I used a phone that was running Ingress and acting as a Wifi access point. I discovered that the cables that Samsung ships with their recent devices (Galaxy Note 2 and Galaxy Note 10.1 tablet) seem to work best and support charging my Galaxy Note 2 or my wife’s Nexus 5 while playing Ingress and running as a Wifi AP. Most of the other cables that I have in my collection won’t even allow a phone to remain at the same charge level while playing Ingress.

AA Emergency Phone Charger

The AA phone charger is best suited for emergency use only, it takes one AA battery and has limited current capacity [3]. A NiMh rechargeable battery has a nominal Voltage of 1.2V, to provide 5V to charge a phone the Voltage has to be boosted by a factor of 4.16 which would reduce the current by a factor of 4.16 if the charger was 100% efficient. As 100% efficiency is impossible the current would be reduced even more. It seems unlikely that a AA battery would be able to sustain a current of 2A so the supply from that charger would be less than 500mA – IE less than the least capable PC USB port or mains powered phone charger. A test with a Nexus 5 showed the phone charge level decreasing while being very lightly used (mostly just checking whether the charge level was increasing) when a NiMH battery was connected. A test with an alkaline battery and the same Nexus 5 showed the phone charge level increasing when lightly used – but it probably wouldn’t do so while playing Ingress.

It seems that a single NiMH AA battery can only be used for charging a phone in a real emergency situation (IE an “act of god” type disaster not a need to level up in Ingress). If mains power was out then you could charge a phone while it’s turned off (AFAIK all Android phones support this) and then use it once it’s charged. This charger supports a wide range of phones (including LG phones from 5+ years ago and Nokia from ~10 years ago) so it could be good for charging an old phone in an emergency. Older phones need less power to charge and generally last longer between charges.

With an alkaline battery the charger works a lot better, but it’s still for emergency use as I generally only use rechargeable batteries. This is a device I might put in the bottom of my case when travelling, not a device that I’ll use regularly. I don’t think that this is a deficiency in the product, it’s just a limit of what can be done with the power requirements of modern phones and the capabilities of AA batteries. If you want a battery to use while playing Ingress you definitely need something a lot larger.

This charger is good for emergencies but not suitable for my main use (charging phones while playing Ingress) so I’ll give it to my parents, they do a lot of hiking and camping and my father often goes fishing. Taking a few AA batteries to charge a phone would be much more convenient for such use than taking one of the larger batteries I use for Ingress. Also as the charger is relatively cheap there’s less potential financial loss if you drop it in sea-water.

20800mAh Battery

picture of 20800mAh USB battery

Above is a picture of a 20800mAh battery pack that MobileZap sent me [4]. I haven’t yet discovered what it’s capacity is, during the recent Interitus anomaly it kept my Galaxy Note 2 and my wife’s Nexus 5 adequately charged for 5 hours of intensive Ingress playing (we alternated between phones). Without an external battery it would be unusual for either of those phones to last for 2 hours.

The battery has two ports labeled 1A and 2.1A which implies that it can supply a total of 3.1A. I am a little dubious of that implication. After the Interitus anomaly my wife and I had dinner with some friends and I let a friend charge her Samsung Galaxy S5 on the battery at the same time as my Note 2 (which claimed to be 2% charged). When I connected my friend’s phone my phone instantly shut itself down due to lack of charge, so I presume that the supply on the 2.1A port is reduced when a demanding device is connected to the 1A port.

The next day my wife and I went to the city again to play Ingress and attend a protest against some of the awful things that the Abbott government is doing. As an experiment I didn’t charge this battery to see how it would go for two days of use charging two phones. Again there was no problem and it still claimed to be half charged when we got home.

So far the only problem I’ve found with this battery is that it never reports being fully charged, not even if I leave it on charge for days. That doesn’t seem to be a great problem to me, if I disconnect it before it’s fully charged then that won’t hurt the battery life (unlike NiCd batteries that have to be fully charged every time) and even if it’s not fully charged it will still charge phones for a long time.

The battery is about 19cm long. I have jeans with unusually large pockets to fit large phones [5] so I can fit this battery in my pocket while a USB cable is connected to charge my phone. I also have a new winter jacket from Scottwear which has pockets that can fit the battery (and lots of other things). Anyone who doesn’t have such clothing should plan to use a backpack, handbag, or some other bag – this type of battery won’t fit in the pockets in most clothing.

MobileZap also has some other interesting Nexus 5 accessories [6].

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Syndicated 2014-06-19 03:21:17 from etbe - Russell Coker

Google Hardware Support

Ironically just 5 days after writing about how I choose Android devices for a long service life [1] my wife’s Nexus 5 (with 32G of RAM to give it a long useful life) totally died. It reported itself as being fully charged and then 15 minutes later it was off and could not be revived. No combination of pushing the power button and connecting the power cable caused the screen to light up or any sound to be emitted.

Google has a nice interactive support site for nexus devices that describes more ways of turning a phone on than any reasonable person could imagine. After trying to turn the phone on in various ways (plugged and unplugged etc) it gave me a link to get phone support. Clicking on that put me in the queue to RECEIVE a phone call and a minute later a lady who spoke English really well (which is unusual for telephone support) called me to talk me through the various options.

Receiving a phone call is a much better experience than making a call. It meant that if the queue for phone support was long then I could do other things until the phone rings. It’s impossible to be productive at other tasks while listening for hold music to stop and a person to start talking. The cost of doing this would be very tiny, while there would be some cost in hardware and software to have a web site that tells me how long I can expect to wait for a call a more basic implementation where I just submit my number and wait for a call would be very cheap to implement. The costs of calls from the US to Australia (and most places where people can afford a high end Android phone) are quite cheap for home users and are probably cheaper if you run a call center. If the average support call cost Google $1 and 3% of phones have support calls then that would be an extra cost of $0.03 per phone. I expect that almost everyone who buys a $450 phone would be happy to pay a lot more than $0.03 to avoid the possibility of listening to hold music!

I received the phone call about a minute after requesting it, this was nice but I wonder how long I would have waited if I hadn’t requested a call at 1AM Australian time (presumably during the day in a US call center). In any case getting a 1 minute response is great for any time of the day or night, lots of call centers can’t do that.

While the phone support is much better than most phone support, it would be nice if they added some extra options. I think it would be good to have webchat and SMS as options for support for the benefit of people who don’t want to speak to strangers. This would be useful to a lot of people on the Autism Spectrum and probably others too.

The phone call wasn’t particularly productive, it merely confirmed that I had followed all the steps on the support website. Then I received an email telling me about the web site which was a waste of time as I’d covered that in the phone call.

I have just replied to their second email which asked for the IMEI of the phone to start the warranty return process. We could have saved more than 24 hours delay if this had been requested in the first email or the phone call. Google could have even requested the IMEI through the web site before starting the phone call. It would have been even easier if Google had included the device IMEI in the email they sent me to confirm the purchase as searching for old email is a lot easier than searching through my house for an old box. Another option for Google would be to just ask me for the Gmail account used for the purchase, as I only bought one Nexus 5 on that account they then have all the purchase details needed for a warranty claim.

While the first call was a great experience the email support following that has been a waste of time. I’m now wondering if they aim to delay the warranty process for a few days in the hope that the phone will just start working again.

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Syndicated 2014-06-10 01:39:58 from etbe - Russell Coker

Android Device Service Life

In recent years Android devices have been the most expensive things I’ve purchased apart from airline tickets and other travel/holiday expenses. As they are expensive I’d like to use them for as long as possible to get the most value for money. Also as I give my devices to relatives when they no longer work for me I’d like to avoid having relatives hassling me about their phone not working as desired. So I’ve been thinking about the features that I need to make it possible to use a phone or tablet for a long time.

RAM

The way Android works is that when an application in the foreground requests more memory background applications may be closed to free some memory. Android doesn’t use swap by default, there is some documentation on how to enable it (and it’s not difficult to figure out for anyone who has used Linux before) but generally it’s not done.

If you run a larger application the chances of apps closing in the background (causing delays when you switch back to them and possibly a loss of context if the app is buggy and doesn’t preserve all state) are increased. As a general trend apps tend to get bigger to provide more features and also because users who own newer bigger devices don’t complain as much about memory use.

Also to make things worse new versions of Android tend to use more RAM. So a phone that runs well can suddenly start performing badly when you upgrade to a new version of Android (which incidentally usually can’t be reversed) and upgrade to new versions of apps (which can’t be reversed through the Google Play Store).

The Sony Ericsson Xperia X10 was a very nice phone when it was released, it ran Android 2.1 very quickly. When I upgraded the Xperia X10s that my wife and I used to Android 2.3 (which was necessary to have the phone run as a Wifi access point) performance dropped considerably. The Android upgrade combined with newer larger apps means that those phones are barely usable now. 384M of RAM was plenty in early 2011 when I first used the Xperia X10 but it’s not nearly enough now.

Recently 2G of RAM has been the minimum for a mid-range or high-end phone. It seems difficult to imagine a new Android feature as compelling as the addition of Wifi access point support in Android 2.3 that would drive an upgrade to a future memory hogging version of the OS. It also seems difficult to imagine Android apps needing enough memory to destroy the performance of a phone with 2G of RAM. But then I couldn’t imagine the 384M in an Xperia X10 becoming inadequate or the 512M in a Samsung Galaxy S becoming barely usable either.

Storage

Until fairly recently storage in an Android device was divided into USB attached storage (a VFAT filesystem that could be directly mounted on a PC) and a Linux filesystem that was used for all internal operations of the phone. On such devices it typically wasn’t possible to change partition sizes without a lot more skill than most users possess and most of the storage space was reserved for USB attachment. If you only had a few Android apps and lots of photos, movies, etc then this worked well. But if you wanted to install larger Android apps then you would have big problems. Even with Android 4.x devices (which all seem to have a single filesystem) you can easily run out of space.

Modern games often take several hundred megs of storage. Games that take 500M+ for the Android package install (which also requires the same amount of temporary space for installation and upgrade) are common. Sometimes games download data files after they have been installed for a total size approaching 2G (such as The Sims Freeplay).

When I bought a Nexus 4 for my wife I got the version with 8G of storage because paying an extra $50 for the 16G version seemed unreasonable. 8G was fine for my wife, but when she got a new phone I gave the Nexus 4 to a relative who wanted to play The Sims and other big games. That relative isn’t so happy about having a limited number of games on their phone and I have to fix it when storage space runs out and things start aborting (when storage runs out the Google App Store program aborts and uses lots of space for temporary files).

I recently bought a tablet with 32G of storage and filled 16G on the first day (tablets are good for watching
TV and TV shows are big). Fortunately the tablet in question has a SD socket so that when space becomes a problem in a year or two I can buy an SD card and keep using it.

An unfortunate recent decision by Google was to prevent apps from being run from a SD card. So even if you have a device with a SD socket you still need to have enough internal storage for all apps and their private data. At 500M+ for a modern game that means a device with 8G of storage (which includes space for the OS) will be lucky to get 8 games installed.

If you want to use a phone to it’s full capacity (playing various media files, games, etc) then it seems that the minimum storage capacity would be 8G of internal storage and a SD socket. For a device without an SD socket (such as the Nexus 5 with 16G or 32G of storage) your future use will be limited. 32G is probably enough for a phone given that you can recode movies to use less space (the FullHD screen on the Nexus 5 is nice but 720p movies will probably look good enough). But the larger screens of tablets demand better video quality so the Nexus tablets are probably a bad choice due to lack of storage space.

Screen Size and Resolution

I have previously written about the sizes of devices and how they may be used by people of various ages [1]. That should be of use for anyone who plans to use their old phone as an educational device for their children (which appears to be very common). But apart from that I can’t think of any reason why size would suddenly make an old phone obsolete. Only young children will have their hands change size in any significant way.

Resolution also shouldn’t be a huge problem, the 480*854 screen on the Xperia X10 is fairly good for a 4″ screen. While a higher resolution makes text more readable at a small size for most users the availability of a higher resolution screen isn’t going to make their old phone obsolete.

CPU

The only Android devices I owned that appeared to develop CPU speed issues late in life were the Xperia X10 phones, and that might be more due to RAM limits and the OS upgrade. All the other devices were either obviously slow at purchase time or are still performing well now.

CPU speed may make it difficult or impossible to play new games, but shouldn’t affect other uses of a phone or tablet.

Conclusion

It seems to me that if you want to use an Android device for more than 2 years then storage capacity should be a major factor in choosing which device to purchase. It seems that lack of storage space is in many cases the main factor that makes older devices annoying or impossible to use.

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Syndicated 2014-06-04 06:05:41 from etbe - Russell Coker

Links May 2014

Charmian Gooch gave an interesting TED talk about her efforts to fight organised crime and corruption by prohibiting anonymous companies [1]. The idea of a company is to protect the owner from unlimited liability not to protect them from law enforcement.

Dr Nerdlove has an insightful article about sexual harassment in geek culture [2].

Rebecca Rose wrote an insightful article for Jezebel about the worse bullying advice ever, her summary is that it should be called “Ways We Can Get You Goddamn Kids to Act So We Never Have to Deal With Your Problems Ever” [3].

In the wake of the Heardbleed bug Imperial Violet wrote an informative article explaining why revocation checks isn’t the solution [4].

Martin Lukacs and Shiri Pasternak wrote an insightful article about the Canadian government’s attempts to stop Canadian aboriginies from exercising their legal rights [5]. I bet that the Australian government is doing the same things.

Nelson Groom wrote an interesting interview with Norrie May Welby, the first recognised agender person in Australia [6]. Marriage equality is bound to happen soon in Australia, now that the government officially recognises non-binary gender people it can’t refuse them the right to get married and therefore the straight/gay marriage distinction isn’t relevant.

BDA Technology has an interesting article on choosing fonts to make text more readable for dyslexic people [7].

Eamon Waterford wrote an informative article for the ABC about how early-intervention social policies save significant amounts of tax money [8]. Conservatives claim to want to save money and try to cut such programs which costs everyone in the long term.

Greta Christina wrote an insightful article for Salon about why religious people want atheists to lie and pretend to believe [9].

Chris Mooney wrote an informative URL about a machine to test whether someone is liberal or conservative [10]. Paul Rosenberg wrote an informative article on the link between conservatism, evil, and psychopathy [11]. The next logical step is to treat conservatism as a mental health problem.

Sociological Images has an interesting article by Jay Livingston about the hypocrisy of “conservative” tax policies [12].

Scientific American reprinted an article from The Conversation by Elaine McKewon about the climate deniers who intimidated a journal into retracting an article about their belief in conspiracy theories [13]. It seems obvious that the climate deniers are the ones who conspire.

Ben Caldecott wrote an interesting article for the ABC about the fossil fuel divestment campaign [14]. It seems that this is getting some success already, as renewable energy will soon be cheaper than coal power this could kill off coal.

Mark Taylor wrote an interesting blog post titled “Observations of an Internet Middleman” about the operations of Level3 and Internet peering [15]. He explains how monopoly Telcos throttle their customers’ Internet access.

Matt Savoy wrote an informative and disturbing article about the fact that US cops are twice as likely to beat their wives as the general population [16]. Apparently the police hierarchy aren’t interested in prosecuting such crimes.

Paul Rosenberg wrote an insightful article about mythos vs logos and the conservative approach to relity [17]. One interesting point he makes is that white men (and members of privileged groups generally) fear a loss of status more than more realistic concerns (such as global warming).

Nick wrote an interesting blog post about using GPG encrypted email on an Android phone [18]. I should get this going on my phone.

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Syndicated 2014-05-29 08:53:51 from etbe - Russell Coker

Why I Use BTRFS

I’ve just had to do yet another backup/format/restore operation on my workstation due to a BTRFS corruption problem, but as usual I didn’t lose any data. The BTRFS data integrity features work reasonably well even when the filesystem gets into a state where the kernel will only accept a read-only mount.

Given that the BTRFS tag on my blog is mostly about problems with BTRFS I think it’s time that I explain why I use it in spite of the problems before people start to worry about my sanity or competence.

The first thing to note is that BTRFS is fairly resiliant toward errors when mounted in read-only mode. When mounting a filesystem read-write there are a number of ways in which things can break which are often due to kernel code not being able to handle corrupt metadata – I don’t know how much of this is inherent to the design of BTRFS and how much is simply missing features in filesystem error handling. Some of the errors that I have had weren’t entirely the fault of BTRFS, I twice had to do a backup/format/restore of my workstation due to a faulty DIMM corrupting memory (that has the potential to mess up any filesystem), but I still didn’t lose any data AFAIK.

The next thing to note is that I don’t use BTRFS when doing paid sysadmin work. ZFS is a solid and reliable filesystem and it is working really well for my clients while BTRFS has too many issues at the moment. As an aside I’m not interested in any comments about the ZFS license situation from anyone who’s not officially representing Oracle.

I also don’t use BTRFS on systems that I can’t access easily. The servers I have running BTRFS are all within an hour’s drive from home, while driving for an hour on account of a kernel or filesystem error is really annoying it’s not as bad as dealing with a remote server where I have no direct access.

Reasons to Use BTRFS

The benefits of BTRFS right now are snapshots (which are good for a first-line backup) and the basic data integrity features. I’ve found these features to work well in real use.

According to the comparison of Filesystems Wikipedia page ZFS and BTRFS are the only general purpose filesystems (IE for disks not tapes, NVRAM, or a cluster) that support checksums for all data and compression. Given that ZFS license issues will never allow it to be included in the Linux kernel tree it seems clear that BTRFS is the next significant filesystem for Linux. More testing of BTRFS is a good thing, while there are a number of known problems that the developers are working on it seems that more testing is needed now to find corner cases. Also we need a lot of testing to find bugs related to interactions with other software.

I’ve recently filed bug reports against the Debian installer because it can’t install to a BTRFS RAID-1 (fortunately BTRFS supports changing to RAID-1 after installation) and because it doesn’t support formatting an existing BTRFS filesystem (the mkfs program needs a -f option in that case). I also sent in a patch for the magic database used by file(1) to provide more information on BTRFS filesystems (which is in Debian/testing but not Debian/Wheezy). These are the sorts of things you encounter when routinely using software that you don’t necessarily notice in basic testing.

As an aside the Debian installation process failed at the GRUB step when I manually balanced a filesystem to use RAID-1 while the Debian installation was in progress. I didn’t file a bug report because the best advice is to not mess with filesystems while the installer is running. I’ll do a lot more testing of this when the Debian installer supports a BTRFS RAID-1 installation.

A final thing that we need to work on is developing sysadmin best practices and scripts for managing BTRFS filesystems. I’ve done some work on scripts to create snapshots for online backups but there are issues of managing free space etc. But working out how to best manage a new filesystem is something that takes years because there are many corner cases you may only encounter after a system has been running for a long time. So I really wouldn’t want to be in the situation of using a new filesystem on an important server without having practice running it on less important systems, I did that with ZFS and now have a hacky first install that I have to support for years.

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Syndicated 2014-05-21 01:18:15 from etbe - Russell Coker

My First Ingress Anomaly

schwag from Ingress Anomaly

Ingress is an Android phone game developed by Google where you have to go to various places to capture “portals” which are based on landmarks or places of note. There’s a sci-fi back story which I haven’t cared much about (my local library has a heap of good sci-fi books I don’t have time to read). But if you are interested in low quality sci-fi you can start with the Youtube channel for Ingress [1]. But the best thing to do is to download the Ingress client program from the Google play store if you have an Android phone [2].

Periodically they have special events in the game called “Anomalies”, which usually involve many people competing to capture a small number of special portals. Usually a portal is fairly easy to capture so a high level player can easily capture a portal in at most a few minutes, but when there is a large group of players defending a portal by replacing the “resonators” as quickly as they are destroyed it becomes more challenging. I’m not going to try to explain this properly as I presume that readers either already know or don’t care. The Wikipedia page about Ingress has more information.

On Saturday there was an Anomaly where the main city was Melbourne. My team (Enlightened) won the event in Australia but apparently the event in the US at the same time was won by the other team (Resistance).

I had hoped that our event would be similar to some of the ones I’ve seen on the “Ingress Report” (a fictional news service on youtube) in which actors from the sci-fi videos about Ingress attended. But unfortunately it seems that the actors stay in the US.

Every player who was registered for the anomaly received a gift pack that contained three cards and a badge. The picture above shows the cards that my wife and I received along with one of our badges. The badges are green for Enlightened and blue for Resistance (the in-game colors) and have three flashing LEDs – the photo has one of the LEDs lit up. The three cards have “passcodes” which can be redeemed for in-game items, the XMP, Power Cubes, and Resonators weren’t that useful (10 not particularly rare items that I could get through 10 minutes of game playing). The “Medal” cards are for in-game badges showing the anomalies that we have played at, but they are “bronze” badges which again aren’t much use as nothing less than silver will help in leveling up.

Overall it was a good experience, we won, had a good after-party (with free snacks and one free drink per person), and the badges are nice. I recommend attending if there’s an event in your area, and note that you don’t need to be a high level player to attend, even L6 players were able to contribute.

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Syndicated 2014-05-19 05:58:21 from etbe - Russell Coker

Mobile Phones and Cognitive Costs

I previously wrote about the case for a Basic Income in Australia [1]. Since then I read an interesting article by Rutger Bregman in the Dutch site The Correspondent discussing the benefit that such Basic Income schemes have given in various places [2], he makes a great case for giving a Basic Income to poor people. However I believe that it should be provided to everyone. I believe that government payments shouldn’t be “means tested” because the proportion of the population who earn more than the cutoff is usually very small (IE it doesn’t save much money), because the money will be recovered from wealthy people in tax, and because the bureaucracy involved in determining who is eligible involves spending tax money to pay bureaucrats and costing everyone time in dealing with the process.

The concept of an Attention Economy has been getting some interest recently. But discussions of it seem to be mostly concerned with the needs of fairly wealthy people, how to advertise to them, how to filter out unwanted ads for them, etc. But the costs in attention can be even worse for people on low incomes or social security because they have many attention costs that could be solved by money. Many common essential purchases (EG soap, basic foods, and purely functional clothes) can become difficult decisions if saving a few dollars is important. The amount of thought involved in buying such items can result in someone who’s not well off having little energy to concentrate on other things. I think that to have an effective social security system we need to consider how much cognitive effort is being required of people who are receiving benefits.

Last month I wrote yet another review of mobile phone plans in Australia [3]. Every time I do this it takes a significant amount of time because the Telcos devise overly complex plans to make it difficult to compare their offerings. It seems that they aim to make their offerings somewhat competitive if you can interpret them but confusing enough to allow many (most?) of their customers to pay needlessly high bills. I could just pick a random telco and pay whatever it takes, spending an extra $10 or $20 per month isn’t such a big deal for me. Even though I advise a number of my relatives on the cheapest phone plan it’s probably only barely saving enough money to be worth the effort, a major motivation for me is being stubborn and not wanting telcos to rip people off.

The Importance of Mobile Phones

A mobile phone seems to be essential for most people. Mobile phones are used for making medical appointments and for applying for work, so in almost every case some of the financial assistance paid to a job seeker or person on a disability pension will go towards mobile phone costs. The aims of the social security benefits seem to clearly involve a phone service. Given that most people who receive social security payments spend some of that money on mobile phone bills the government has a direct financial interest in not having such money wasted on needlessly expensive phone plans. As we also don’t want to have people on social security spending time and attention trying to find the best phone plan it makes sense to have the government help manage this process.

Good communications is regarded as essential to education and economic development. A huge amount of taxpayer money was spent on the NBN (and then wasted by Tony Abbott when he cancelled the original plans) for these benefits.

Good phone access is also an issue of personal safety. While it is possible to call emergency services from a mobile phone that doesn’t have a valid SIM there are probably few people who keep a spare phone charged for that purpose. Also there are a variety of issues that can impact life or health which can best be resolved by calling friends or relatives.

Free Phones

I think that the best solution to these problems is for the government to directly pay mobile phone bills. If we are going to have a Basic Income then the government should make the base payment for mobile phone calls for every resident, if not then the government should make the base payment for everyone who receives any form of social security payment. Obviously the amount of data that could be transferred over a 3G network is greatly in excess of the amount that any plans allow and offering true “unlimited” calling leads to people using mobile phones as baby-monitors, so some limits are necessary. But the government could cheaply pay for a phone plan that exceeds the requirements of most people and then allow anyone who wants more data or calls to pay extra.

Which Plan?

The cheapest all-inclusive mobile phone plan in recent times was Kogan who charged $299 per annum for 6G of data per month and “unlimited” calls. The cheapest current offer for “unlimited” calls seems to be Lebara’s $30 per month offer which includes 2G of data.

My observation is that people who use 3G Internet just for phone use (as opposed to tethering a laptop or providing home Internet), who use a home Wifi network for installing Android programs and don’t play Ingress tend to use a lot less than 1G of data per month. I would use between 400M and 700M per month if I wasn’t playing Ingress and didn’t use my phone as a Wifi access point.

In terms of call volume, 600 minutes a month should be enough to cover the basic needs of most people judging by the number of plans on offer with limits smaller than that.

As a current Lebara offer is $30 per month for “unlimited” calls and 2G of data (and there are similar offers from other telcos), it should be possible for a telco to offer 600 minutes of calls and 1G of data for less than $15 per month. When the government is paying (no bad debts) and many of the users will use much less than the quota such a plan should be profitable at $10 per month or less.

Implementation

The way to implement this would be to start with a tender that has a hard requirement for the minimum amount of service provided. This would include the number of minutes per month for calls, the number of SMS sent, and the amount of data transfer. To avoid excessive billing (a standard telco scam) there should be a requirement that fees for extra use not exceed some small multiple of the base rate, for example if the government was paying $10 for 600 minutes of calls and 1G of data the excess usage charges could be capped at 3 cents per meg and 5 cents per minute (3* the base rate) which would be profitable for the telco but not a scam.

If the telcos act in a market driven competitive manner they will compete to provide the most attractive offerings for $10 per month.

If the build cost of the NBN had been invested at government bond rates (for any of the rates used for current bonds) then it would pay for the mobile phone bills for every resident forever, so the cost of providing phones for everyone is in the range of government telecommunications programs. If people who are working were to pay an extra $10 in tax and people who are on social security had their benefits reduced by $10 then that would be a great deal if it saved them the $20 or more that most people spend on a basic phone plan.

Government Phone Delays

A friend who’s a single mother pays for an “unlimited” mobile phone plan because calls to the social security office are usually kept on hold for more than an hour. It’s likely that she could save money over the course of a year by paying for a cheaper plan and just dealing with the occasional big bill, but she needs to budget carefully and feels that she can’t take that risk. It seems stupid that government phone delays (partly caused by cutting funds for staff) cause increased expenses for people who are receiving social security payments. If the government implemented a smart queuing system that allowed them to call people back instead of making them wait on hold then it would save money overall.

So there are obviously other ways that the government can save money on phone calls and time for everyone.

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Syndicated 2014-05-15 07:53:52 from etbe - Russell Coker

BTRFS vs LVM

For some years LVM (the Linux Logical Volume Manager) has been used in most Linux systems. LVM allows one or more storage devices (either disks, partitions, or RAID sets) to be assigned to a Volume Group (VG) some of which can then allocated to a Logical Volume (LVs) which are equivalent to any other block device, a VG can have many LVs.

One of the significant features of LVM is that you can create snapshots of a LV. One common use is to have multiple snapshots of a LV for online backups and another is to make a snapshot of a filesystem before making a backup to external storage, the snapshot is unchanging so there’s no problem of inconsistencies due to backing up a changing data set. When you create a snapshot it will have the same filesystem label and UUID so you should always mount a LVM device by it’s name (which will be /dev/$VGNAME/$LVNAME).

One of the problems with the ReiserFS filesystem was that there was no way to know whether a block of storage was a data block, a metadata block, or unused. A reiserfsck --rebuild-tree would find any blocks that appeared to be metadata and treat them as such, deleted files would reappear and file contents which matched metadata (such as a file containing an image of a ReiserFS filesystem) would be treated as metadata. One of the impacts of this was that a hostile user could create a file which would create a SUID root program if the sysadmin ran a --rebuild-tree operation.

BTRFS solves the problem of filesystem images by using a filesystem specific UUID in every metadata block. One impact of this is that if you want to duplicate a BTRFS filesystem image and use both copies on the same system you need to regenerate all the checksums of metadata blocks with the new UUID. The way BTRFS works is that filesystems are identified by UUID so having multiple block devices with the same UUID causes the kernel to get confused. Making an LVM snapshot really isn’t a good idea in this situation. It’s possible to change BTRFS kernel code to avoid some of the problems of duplicate block devices and it’s most likely that something will be done about it in future. But it still seems like a bad idea to use LVM with BTRFS.

The most common use of LVM is to divide the storage of a single disk or RAID array for the use of multiple filesystems. Each filesystem can be enlarged (through extending the LV and making the filesystem use the space) and snapshots can be taken. With BTRFS you can use subvolumes for the snapshots and the best use of BTRFS (IMHO) is to give it all the storage that’s available so there is no need to enlarge a filesystem in typical use. BTRFS supports quotas on subvolumes which aren’t really usable yet but in the future will remove the need to create multiple filesystems to control disk space use. An important but less common use of LVM is to migrate a live filesystem to a new disk or RAID array, but this can be done by BTRFS too by adding a new partition or disk to a filesystem and then removing the old one.

It doesn’t seem that LVM offers any benefits when you use BTRFS. When I first experimented with BTRFS I used LVM but I didn’t find any benefit in using LVM and it was only a matter of luck that I didn’t use a snapshot and break things.

Snapshots of BTRFS Filesystems

One reason for creating a snapshot of a filesystem (as opposed to a snapshot of a subvolume) is for making backups of virtual machines without support from inside the virtual machine (EG running an old RHEL5 virtual machine that doesn’t have the BTRFS utilities). Another is for running training on virtual servers where you want to create one copy of the filesystem for each student. To solve both these problems I am currently using files in a BTRFS subvolume. The BTRFS kernel code won’t touch those files unless I create a loop device so I can only create a loop device for one file at a time.

One tip for doing this, don’t use names such as /xenstore/vm1 for the files containing filesystem images, use names such as /xenstore/vm1-root. If you try to create a virtual machine named “vm1″ then Xen will look for a file named “vm1″ in the current directory before looking in /etc/xen and tries to use a filesystem image as a Xen configuration file. It would be nice if there was a path for Xen configuration files that either didn’t include the current directory or included it at the end of the list. Including the current directory in the path is a DOS mistake that should have gone away a long time ago.

Psychology and Block Devices

ZFS has a similar design to BTRFS in many ways and has some similar issues. But one benefit for ZFS is that it manages block devices in a “zpool”, first you create a zpool with the block devices and after that you can create ZFS filesystems or “ZVOL” block devices. I think that most sysadmins would regard a zpool as something similar to LVM (which may or may not be correct depending on how you look at it) and immediately rule out the possibility of running a zpool on LVM.

BTRFS looks like a regular Unix filesystem in many ways, you can have a single block device that you mount with the usual mount command. The fact that BTRFS can support multiple block devices in a RAID configuration isn’t so obvious and the fact that it implements equivalents to most LVM functionality probably isn’t known to most people when they start using it. The most obvious way to start using BTRFS is to use it just like an Ext3/4 filesystem on an LV, and to use LVM snapshots to backup data, this is made even more likely by the fact that there is a program to convert a ext2/3/4 filesystem to BTRFS. This seems likely to cause data loss.

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Syndicated 2014-05-12 07:37:50 from etbe - Russell Coker

Source Escrow for Proprietary Software

British taxpayers are paying for extra support for Windows XP due to a lack of planning by the UK government [1]. While the cost of this is trivial compared to other government stupidity (such as starting wars of aggression) this sort of thing should be stopped.

The best way to solve such problems is for governments to only use free software. If the UK government used Red Hat Enterprise Linux then when Red Hat dropped support for old versions they would have the option of providing their own support for old versions, hiring any other company to support old versions, or paying Red Hat for supporting it. In that case the Red Hat offer would probably be quite reasonable as competition drives the prices down.

It doesn’t seem likely that the UK government will start using only free software in the near future. It’s not impossible to do so, there are organisations dedicated to this task such as Free-gov.org which aims to develop e-government software that is under GPL licenses [2]. The Wikipedia page List of Linux Adopters [3] has a large section on government use, while not all entries are positive (some have reverted) it shows that it’s possible to use Linux for all areas of government. But governments often move slowly and in the case of wealthy countries such as the UK it can be easier to just tax the citizens a little more than to go to the effort of saving money.

But when governments use proprietary software they shouldn’t be restricted in support. It seems that the only way to ensure that the government can do what it needs is to have a source escrow system. Then if the company that owned the software ceased supporting it anyone who wanted to offer support would be able to do so. This would probably require that software which is out of support be released to the public domain so that anyone who wanted to tender for such support work could first inspect the code to determine if they were capable of doing the work.

People who believe the myths about secret source software claim that allowing the source code to be released would damage the company that owns it. This has been proved incorrect by the occasions when source code for software such as MS-Windows has been released on the Internet with no apparent harm. Also Microsoft have a long history of licensing their source code to universities, governments, and other companies for various purposes (including porting Windows to other CPUs). It’s most likely that some part of the UK government already has the full source code to Windows XP, and it’s also quite likely that computer criminals have obtained copies of the source by now for the purpose of exploiting security flaws. Also they stop supporting software when they can’t make money from providing the usual support, so by definition the value to a company of the copyright is approaching zero by the time they decide to cease support.

Given the lack of success experienced by companies that specialise in security (for example the attack on RSA to steal the SecurID data [4]) it doesn’t seem plausible that Microsoft has had much success in keeping the source to Windows XP (or any other widely used product) secret over the course of 12 years.

In summary source code to major proprietary software products is probably available to criminals long before support expires and is of little value to the copyright owners. But access to it can provide value to governments and other users of the software.

The only possible down-side to the software vendor is if the new version doesn’t provide any benefits to the user. This could be a problem for Microsoft who seem to have the users hate every second version of Windows enough to pay extra for the old version. The solution is to just develop quality software that satisfies the needs of the users. Providing a legal incentive for this would be a good idea.

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Syndicated 2014-05-03 05:50:31 from etbe - Russell Coker

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