Facebook And Online Privacy

 Computing, Politics  No Responses »
Nov 232007
 

Today the UK’s Information Commissioner announced that today’s young (and in some cases not so young!) are putting their future careers at risk with some of their ‘riskier’ posts on social networking sites such as Facebook. In addition they pointed out that they were risking identity theft by putting so much personal information online.

It is worth mentioning that information can live online for a very long time … forever if the people behind Archive.Org have their way. This is not necessarily a bad thing although it can come as a nasty shock to realise just how shallow one was as a youth!

But do employers really care what people put on their Facebook profiles ? Well I dare say some do, but they probably should not. I’ve had more than my fair share of ‘youthful excesses’ in the distant past, but I’ve been a reasonably productive employee for all of that time. Now some more conservative companies may be worried about people making an association between their Facebook profile and the company they work for … fair enough. It seems perfectly reasonable to have a policy to say that one’s Facebook profile should not be linked to one’s place of work.

But not to employ someone because their Facebook profile looks a little wild ? That probably counts as cutting off one’s nose to spite your face! And quite possibly may count as age discrimination!

Now I come to identity theft. It is true that having too many personal details online may well make you more subject to identity theft which is a serious problem (although not a new one!). But is eliminating personal details online the right way of tackling the problem ? We have also seen this week that people can be subjected to the risk of identity theft through no fault of their own. Those who do not follow computer security news closely, may not realise that this is a story that is regularly repeated although not usually on such a scale.

Whilst being careful about putting personal details online is undoubtedly good practice (because no other solution is going to arrive quickly) we need to think about better ways of defending against identity theft other than hiding personal details. I have no ideal how this might be done in detail, although one obvious thing occurs … to have multiple ‘keys’ which serve different purposes … perhaps a government ‘key’, a financial ‘key’, a ‘social networking key’ (for things like Facebook and online forums), and a ‘key’ to be used for employer identity purposes. Seperating these ‘keys’ would limit the damage if a leak did occur … essentially you would need to steal multiple ‘keys’ to steal someone’s identity.

The problem of identity theft is only going to get worse unless we do something better in the future. Basing one’s identity on things like address, birth date, etc. is not going to be anywhere near like secure enough. It has always been possible to steal someone’s identity if you have these details, but the pervasiveness of IT systems makes it easier.

In the computer security world there is a truism that ‘security through obscurity is no security at all’, and what we are currently doing to protect our identity is attempting to practice security through obscurity.

Japan To Start Slaughtering Humpback Whales

 Politics  No Responses »
Nov 212007
 

It has recently been announced that the Japanese government has decided to start killing humpback whales for ‘scientific’ research.

Of course nobody with more than half a brain cell really believes that any kind of serious research takes place with the whales that Japan catches. Ignoring all the other whales than Japan catches, what kind of research needs fifty humpbacks?

The truth is that the Japanese government is lying through it’s teeth when it claims that their whaling boats are slaughtering whales for scientific research. It is really just commercial whaling by another name. Which of course is banned by international treaty.

Strangely the Japanese government has to publicise the ‘benefits’ of torturing whales to death for food because there is not as much demand for whale meat as their existing ‘scientific’ research supplies. So why do they need to add humpback whales to the larder ? Seems that Japanese politicians can give politicians everywhere a good challenge when it comes to knuckle-dragging stupidity.

The Japanese government has labelled those who protest against the hunting of whales ‘environmental terrorists’ which is a bit rich considering the protesters do not try to kill anyone! But if we’re going to start splattering the ‘terrorist’ label around wildly, the phrase ‘environmental terrorists’ works quite well for the Japanese government.

Photography: B&W vs Colour

 Photography  No Responses »
Nov 182007
 

As someone who has a preference for making black and white images, but frequently gets asked ‘what does that look like in colour’, and likes colour images, I sometimes wonder about the differences between B&W and colour. In addition I also recently saw an episode of the BBC’s “Genius Of Photography” where it was commented that in the 1970s, colour photography was not taken seriously in the art photography world.

Personally I think it is up to the photographer to decide what kind of image to make … B&W or colour. It is their choice of how to make the image to draw attention to those aspects of the image the photographer wants to draw attention to.

B&W images are supposedly more artistic and colour images are supposedly more realistic. The first is ridiculous … does anyone criticise painters for their ‘unartistic’ use of colour ? And the second is almost as silly … sure the real world is in colour, but it is not frozen in time.

B&W images do tend to make it easier for me to see the geometry and patterns in an image, and give a different slant to the light in the image. But images in colour let you see the colour which is just as important; or more so in some images.

Both are equally valid.

IT: Why ZFS In OSX Is Good For “Ordinary” Users

 Computing  No Responses »
Nov 072007
 

I have been spending some time looking up information on ZFS for OSX because I’ve used ZFS under Solaris and would quite like it on my new Macbook. In many of the places I looked, there were tons of comments wondering why ZFS would be of any use for ordinary users. Oddly the responders indicating features that are more useful for servers than workstations. The doubters were responding with “So?”.

This is perhaps understandable because most of the information out there is for Solaris ZFS and tends to concentrate on the advantages for the server (and the server administrator). This is perhaps unfortunate because I can see plenty of advantages for ordinary users.

I will go through some of the advantages of ZFS that may work for ordinary users. In some cases I will give examples using a command-line. Apple will undoubtedly come up with a GUI for doing much of this, but I don’t have access to that version of OSX and the command-line still works.

ZFS Checks Writes

Unlike most conventional filesystems, ZFS does not assume that hard disks are perfect and uses checks on the data it writes to ensure that what gets read back is what was written. As each “block” is written to disk, ZFS will also write a checksum; when reading a “block” ZFS will verify that the block read matches the checksum.

This has already been commented on by people using ZFS under Solaris as showing up problematic disks that were thought to be fine. Who wants to lose data ?

This checksum checking that zfs does will not protect from the most common forms of data loss … hard disk failures or accidentally removing files. But it does protect against silent data corruption. As someone who has seen this personally, I can tell you it is more than a little scary with mysterious problems becoming more and more common. Protecting against this is probably the biggest feature of ZFS although it is not something that is immediately obvious.
ZFS Filesystems Are Easy To Create

So easy in fact that it frequently makes sense to create a filesystem where in the past we would create a directory. Why? So that it is very easy and quick to see who or what is using all that disk space that got eaten up since last week.

Lets assume you currently have a directory structure like :-

/Users/mike
/Users/john
/Users/stuart
/Users/stuart/music
/Users/stuart/photos

If those directories were ZFS filesystems you could instantly see how much disk space is in use for each with the command zfs list

% zfs list
NAME                                 USED   AVAIL   REFER   MOUNTPOINT
zpool0                               3.92G  23G     3.91M   /zpool0
zpool0/Users/mike                    112M   23G     112M    /Users/mike
zpool0/Users/john                    919M   23G     919M    /Users/john
zpool0/Users/stuart                  309M   23G     309M    /Users/stuart
zpool0/Users/stuart/music            78G    23G     78G     /Users/stuart/music
zpool0/Users/stuart/photos           12G    23G     12G     /Users/stuart/photos

With one very simple (and quick) command you can see that Stuart is using the most space in his ‘music’ folder … perhaps he has discovered Bittorrent! The equivalent for a series of directories on a normal filesystem can take a long time to complete.

With any luck Apple will modify the Finder so that alongside the option to create a new folder is a new option to “create a new folder as a ZFS filesstem” (or something more user-friendly).

It may seem silly to have many filesystems when we are used to filesystems that are fixed in size (or are adjustable but in limited ways), but zfs filesystems are allocated out of a common storage pool and grow and shrink as required.

ZFS Supports Snapshots

Heard of “Time Machine” ? Nifty isn’t it ?

Well ZFS snapshots do the same thing … only better. Time Machine is pretty much limited to an external hard disk which is all very well if you happen to have one with you, but not much use when you only have a single disk. ZFS snapshots work “in place” and are instantaneous. In addition you can create a snapshot when you want to … for instance just before starting to revise a large document so that if everything goes wrong you can quickly revert.

Time Machine has one little disadvantage … if you modify a very large file, it will need to duplicate the entire file multiple times. For instance if you have a 1Gbyte video that you are editing over multiple days, Time Machine will store the entire video every time it ‘checkpoints’ the filesystem. This can add up pretty quick, and could be a problem if you work on very large files. Zfs snapshots stores only the changes to the file (although an application can accidentally ‘break’ this) making it far more space efficient.

One thing that zfs snapshots does not do that Time Machine does, is to ensure you have a backup of your data on an external hard disk. The zfs equivalent is the zfs send command which sends a zfs snapshot “somewhere”. The somewhere could be to a zfs storage pool on an external hard disk, to a zfs pool on a remote server somewhere (for instance an external hard disk attached to your Mac at work to give you offsite backups), or even to a storage server that does not understand ZFS! And yes you can send “incrementals” in much the same way too.

Currently using zfs send (and the opposite zfs receive) requires inscrutable Unix commands, but somebody will soon come up with a friendlier way of doing it. Oh! It seems they already have!

Unfortunately I’ve found out that using ZFS with Leopard is currently (10.5.0) pretty difficult … the beta code for ZFS is hard to get hold of, and may not be too reliable. Funnily enough this mirrors what happened when Solaris 10 first came out … ZFS was not ready until the first update of Solaris 10!

Unfortunately it seems that Apple have retreated back from using ZFS in OSX which is a great shame, and until they come up with something better, we are stuck with HFS+, which means not only do we lack the features of a modern filesystem, but we are also stuck with slow fsck times. Ever wonder why sometimes that blue screen of a Mac starting sometimes takes much longer ? The chances are that it is because a filesystem is being checked – something that isn’t necessary with a modern filesystem.

Wildcat Postal Strikes

 Politics  No Responses »
Oct 102007
 

Like most people in the UK, I am suffering from a lack of postal deliveries because of an official strike that ended today (with rolling strikes due to start next week) … I have several parcels stuck waiting for delivery and it is more than a little frustrating! I was more than a little surprised (and initially annoyed) when the early morning news announced at least one wildcat (unofficial) strike taking place.

Fortunately the media let slip a little detail about why the wildcat strikes started. It seems that the post office managers had changed the working hours without talking it over with the union first. Now perhaps many people reading this will think the managers had every right to change the working hours without negotiating with the work force … personally I disagree, but I am not going over that issue.

The postal workers returned to work at 5:15am (or a similar time … it has been a few hours now) probably in a bit of a militant mood (I’ve been on strike myself and it has that effect), but mostly also keen to get on with dealing with the large piles of unprocessed post. Only to be told by the managers that the hours had changed and they would not get paid for the work done before 6:00am.

Now in normal circumstances the workers would have been prepared for this change … they may not have been happy about it, but they would know and would probably casually mention it to each other on the way home the previous night. Anyone who forgot would probably just slap themselves on their forehead and think “how dumb am I?” (I’ve done something very similar myself).

But these are obviously not normal circumstances. Communications between workers and managers tend to break down during a strike, and the workers may not have been aware of the change or they could have thought that it would be quietly dropped, or simply forgotten about it. And anyone with any sense would see that quietly dropping the change in working hours for now would be diplomatic.

Again there are those who say that the managers had the “right” to change the working hours, and again that’s not the point. The point is that making workers who are keen to get stuck into that big pile of letters and parcels (and most probably were keen) either wait for nearly an hour or to work for free is not likely to encourage good worker-management relations. And in these particular circumstances is likely to provoke exactly what we have seen … wildcat strikes.

Whilst the wildcatters probably deserve a bit of condemnation for what they are doing, it would seem that gross stupidity on the part of the management also deserves some of the blame.

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