Windows

A Call For A Filesystem Abstraction Layer

Filesystems are fundamental things for computer systems: after all, you need to store your data somewhere, somehow. Modern operating systems largely use the same concepts for filesystems: a file’s just a bucket that holds some bytes, and files are organised into directories, which can be hierarchical. Some fancier filesystems keep track of file versions and have record-based I/O, and many filesystems now have multiple streams and extended attributes. However, filesystem organisation ideas have stayed largely the same over the past few decades.

I’d argue that the most important stuff on your machine is your data. There are designated places to put this data. On Windows, all the most important stuff on my computer should really live in C:\Documents and Settings\Andre Pang\My Documents. In practice, because of lax permissions, almost everyone I know doesn’t store their documents there: they splatter it over a bunch of random directories hanging off C:\, resulting in a giant lovely mess of directories where some are owned by applications and the system, and some are owned by the user.

Mac OS X is better, but only because I have discipline: /Users/andrep is where I put my stuff. However, I’ve seen plenty of Mac users have data and personal folders hanging off their root directory. I’m pretty sure that my parents have no idea that /Users/your-name-here is where you are meant to put your stuff, and to this day, I’m not quite sure where my dad keeps all his important documents on his Mac. I hope it’s in ~/Documents, but if not, can I blame him? (UNIX only gets this right because it enforces permissions on you. Try saving to / and it won’t work. If you argue that this is a good thing, you’re missing the point of this entire article.)

One OS that actually got this pretty much correct was classic Mac OS: all system stuff went into the System folder (which all the Cool Kids named “System ƒ”, of course). The entire system essentials were contained in just two files: System, and Finder, and you could even copy those files to any floppy disk and make a bootable disk (wow, imagine that). The entire rest of the filesystem was yours: with the exception of the System folder, you organised the file system as you pleased, rather than the filesystem enforcing a hierarchy on you. The stark difference in filesystem organisation between classic Mac OS and Mac OS X is largely due to a user-centric approach for Mac OS from the ground-up, whereas Mac OS X had to carry all its UNIX weight with it, so it had to compromise and use a more traditionally organised computer filesystem.

As an example, in Mac OS X, if you want to delete Photoshop’s preferences, you delete the ~/Library/Preferences/com.adobe.Photoshop.plist file. Or; maybe you should call it the Bibliothèque folder in France (because that’s what it’s displayed as in the Finder if you switch to French)… and why isn’t the Preferences folder name localised too, and what mere mortal is going to understand why it’s called com.adobe.Photoshop.plist? On a technical level, I completely understand why the Photoshop preferences file is in the ~/Library/Preferences/ directory. But at a user experience level, this is a giant step backwards from Mac OS, where you simply went to the System folder and you trashed the Adobe Photoshop Preferences file there. How is this progress?

I think the fundamental problem is that Windows Explorer, Finder, Nautilus and all the other file managers in the world are designed, by definition, to browse the filesystem. However, what we really want is an abstraction level for users that hides the filesystem from them, and only shows them relevant material, organised in a way that’s sensible for them. The main “file managers” on desktop OSs (Finder and Windows Explorer) should be operating at an abstraction level above the filesystem. The operating system should figure out where to put files on a technical (i.e. filesystem) level, but the filesystem hierarchy should be completely abstracted so that a user doesn’t even realise their stuff is going into /Users/joebloggs.

iTunes and iPhoto are an example of what I’m advocating, because they deal with all the file management for you. You don’t need to worry where your music is or how your photos are organised on the filesystem: you just know about songs and photos. There’s no reason why this can’t work for other types of documents too, and there’s no reason why such an abstracted view of the filesystem can’t work on a systemwide basis. It’s time for the operating system to completely abstract out the filesystem from the user experience, and to turn our main interaction with our documents—i.e. the Finder, Windows Explorer et al—into something that abstracts away the geek details to a sensible view of the documents that are important to us.

One modern operating system has already done this: iOS. iOS is remarkable for being an OS that I often forget is a full-fledged UNIX at its heart. In the iOS user experience, the notion of files is completely gone: the only filenames you ever see are usually email attachments. You think about things as photos, notes, voice memos, mail, and media; not files. I’d argue that this is a huge reason that users find an iPhone and iPad much more simple than a “real” computer: the OS organises the files for them, so they don’t have to think that a computer deals with files. A computer deal with photos and music instead.

There are problems with the iOS approach: the enforced sandboxing per app means that you can’t share files between apps, which is one of the most powerful (and useful) aspects of desktop operating systems. This is a surmountable goal, though, and I don’t think it’d be a difficult task to store documents that can be shared between apps. After all, it’s what desktop OSs do today: the main challenge is in presenting a view of the files that are sensible for the user. I don’t think we can—nor should—banish files, since we still need to serialise all of a document’s data into a form that’s easily transportable. However, a file manager should be metadata-centric and display document titles, keywords, and tags rather than filenames. For many documents, you can derive a filename from its metadata that you can then use to transport the file around.

We’ve tried making the filesystem more amenable to a better user experience by adding features such as extended attributes (think Mac OS type/creator information), and querying and indexing features, ala BFS. However, with the additional complexity of issues such as display names (i.e. localisation), requiring directory hierarchies that should remain invisible to users, and the simple but massive baggage of supporting traditional filesystem structures (/bin/ and /lib/ aren’t going away anytime soon, and make good technical sense), I don’t think we can shoehorn a filesystem browser anymore into something that’s friendly for users. We need a filesystem abstraction layer that’s system-wide. iOS has proven that it can be done. With Apple’s relentless progress march and willingness to change system APIs, Linux’s innovation in the filesystem arena and experimentation with the desktop computing metaphor, and Microsoft’s ambitious plans for Windows 8, maybe we can achieve this sometime in the next decade.

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Irony

Go Microsoft:

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Choice Isn't Always a Good Thing

You know that Which Operating System Are You quiz?

Well, they’re gonna have to expand it to include all six versions of Windows Vista, whenever that decides to be unleashed unto the world. Hello, six versions? With the starter edition only being able to use 256MB of RAM and run three applications at once? Even eWeek says that “you would be better off running Windows 98”. You know what, instead of choosing between Vista Starter, Vista Home Basic, Vista Home Premium, Vista Business, Vista Enterprise or Vista Ultimate, how about I just run Mac OS X or Linux instead, you stupid tossers?

Jesus, the excellent lads over at Microsoft Research (who produce some truly world-class work) must be just cringing when they hear their big brother company do totally insane stuff like this.

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Pushing the Limits

OK, this is both ridiculous and cool at the same time. I need to write code for Mac OS X, Windows and Linux for work, and I like to work offline at cafes since I actually tend to get more work done when I’m not on the Internet (totally amazing, I know). This presents two problems:

  1. I need a laptop that will run Windows, Mac OS X and Linux.
  2. I need to work offline when we use Subversion for our revision control system at work.

Solving problem #1 turns out to be quite easy: get a MacBook (Pro), and run Mac OS X on it. Our server runs fine on Darwin (Mac OS X’s UNIX layer), and I can always run Windows and Linux with Parallels Desktop if I need to.

For serious Windows coding and testing, though, I actually need to boot into real Windows from time to time (since the program I work on, cineSync, requires decent video card support, which Parallels doesn’t virtualise very well yet). Again, no problem: use Apple’s Boot Camp to boot into Windows XP. Ah, but our server requires a UNIX environment and won’t run under Windows! Again, no problem: just install coLinux, a not very well known but truly awesome port of the Linux kernel that runs as a process on Windows at blazing speeds (with full networking support!).

Problem #2 — working offline with Subversion — is also easily solved. Download and install svk, and bingo, you have a fully distributed Subversion repository. Hack offline, commit your changes offline, and push them back to the master repository when you’re back online. Done.

Where it starts to get stupid is when I want to:

  • check in changes locally to the SVK repository on my laptop when I’m on Mac OS X…
  • and use those changes from the Mac partition’s SVK repository while I’m booted in Windows.

Stumped, eh? Not quite! Simply:

  • purchase one copy of MacDrive 6, which lets you read Mac OS X’s HFS+ partitions from Windows XP,
  • install SVK for Windows, and
  • set the %SVKROOT% environment variable in Windows to point to my home directory on the Mac partition.

Boom! I get full access to my local SVK repository from Windows, can commit back to it, and push those changes back to our main Subversion server whenever I get my lazy cafe-loving arse back online. So now, I can code up and commit changes for both Windows and the Mac while accessing a local test server when I’m totally offline. Beautiful!

But, the thing is… I’m using svk — a distributed front-end to a non-distributed revision control system — on a MacBook Pro running Windows XP — a machine intended to run Mac OS X — while Windows is merrily accessing my Mac HFS+ partition, and oh yeah, I need to run our server in Linux, which is actually coLinux running in Windows… which is, again, running on Mac. If I said this a year ago, people would have given me a crazy look. (Then again, I suppose I’m saying it today and people still give me crazy looks.) Somehow, somewhere, I think this is somewhat toward the evil end of the scale.

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MacBook Pro Fun

I suspect that if you don’t know that Apple released their Boot Camp tool to enable normal PC operating systems to be installed on their shiny new ICBMs, you’re probably not a geek, and this article doesn’t really concern you…

Since there have been plenty of other articles written about Boot Camp and its implications for the future of the Macintosh, I won’t say any more about it here. I just wanted to say the following:

  • Tuesday, April 4: Pick up shiny new MacBook Pro from my local AppleCentre.
  • Wednesday, April 5, ~8pm Australian CST: Apple announces Boot Camp.
  • Thursday, April 5, ~2am Australian CST: Windows XP SP2 installs on my Mac.
  • Thursday, April 5, ~3am Australian CST: Visual C++ Express 2005 and Counter-Strike are installed (the latter running at a rather nice 72.7fps in Valve’s Video Stress Test).
  • Thursday, April 5, sometime later: Parallels announces a beta of their Workstation product, enabling Macs to virtualise running guest operating systems. Hooray for x86 hardware virtualisation technology.

Not bad for the first three days of owning a MacBook Pro, really. Bring on the tech!

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ext2fs IFS

Well, some kind-hearted soul has finally written a kernel-mode Installable File System (IFS) ext2 driver for Windows NT/2000/XP. While it ain’t no reiserfs driver for Mac OS X (now that’d be worth some serious restecp), it’s still rather schmick. Plus, now that free kernel-mode ext2 drivers are available for all the major desktop operating systems, hopefully we’re one step closer to destroying FAT as the lowest common denominator filesystem once and for all…

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coLinux

We needed to set up some Annodex servers for demos this week, and our server software currently runs best on Linux. So, what to do if you’re using Windows machines which you can’t install Linux on for whatever reason, political or technical? Run Linux inside Windows, of course, via coLinux.

coLinux is great. No, scratch that — coLinux is really great. Not only does it work, it works really well: it’s fast (I really don’t think I’ve ever seen a Debian system boot up in 2-3 seconds), it’s stable, and it even uses a pretty small amount of memory, since Linux servers tend to be on the trim side. A full-blown Linux installation for us with Apache serving multi-megabyte multimedia streams to multiple Windows clients was using up less than 30MB of Windows’s memory pool. Low fat.

If you must have Windows on your desktop/laptop for whatever reason, but need Linux and are getting sick of doing the reboot dance just to switch OSs, give coLinux a whirl. And, if you want to get geek cred points, watch your friends’ jaws drop when they see X11 applications hosted on coLinux displaying in Cygwin/X; it’s pretty scary just how well it all works. Now, whither my coLinux for Mac OS X port (and flying car)?

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