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How To Implement A Database Oriented File System

Posted by ryuzaki0 on from the something-to-think-about dept.

ALundi writes "A really great read from Andrew Orlowski over at The Register on how Benoit Schillings and Dominic Giampaolo created the 64-bit journaled and attribute based Be File System. Schillings and Giampaolo discuss a variety of design and implementation issues, including data integrity and file system performance. " Interesting in the context of MSFTs plans to implement a DB filesystem in future versions of MS Windows.

2 of 232 comments (clear)

  1. Dominic's Book by jimm · · Score: 5, Informative

    Dominic's book, Practical File System Design with the Be File System, is wonderful. I'd never delved into the innards of a file system before. Reading his book was enjoyable and interesting. I learned quite a lot.

    --
    Transcript show: self sigs atRandom.
  2. Integrated database computers: IBM AS/400 by octogen · · Score: 5, Informative

    It's really not Microsoft's innovation.

    IBM's AS/400 (a midrange computer system targeted for commercial use/accounting/warehouse/etc...) is based on an object-oriented database filesystem which is implemented at the firmware level (SLIC) rather than at the OS-level - and this system has been around for about 20 years and IIRC it always had quite good performance.

    -arch----

    A few words about its architecture, if you're interested...

    The operating system (OS/400) itself runs on top of this object-oriented low-level "OS" by calling its APIs - as a result, most parts of OS/400 are platform-independent. If you'd manage to get the SLIC running on another hardware platform, you could probably install a nearly unmodified version of OS/400, and it would do its work.

    Actually, I'd call the SLIC code the 'real' operating system kernel rather than OS/400, because OS/400 itself would not work without an apropriate SLIC layer.

    Everything on the system is an object, so you'll always have to use the object's methods to perform some operation.
    For some applications that may be an advantage, because security is enforced on each object at the firmware level. For other applications it might also be a disadvantage, because you'll always have to use a limited set of APIs for modifying data. That blocks many methods commonly used for writing highly optimized code.

    -end arch----

    One of the benefits of having a database-filesystem is probably the fact that you do not need to run a database product on top of the OS.
    Every object on the system can be backed up and restored in a very simple way. Logical files (multiple logical views of one physical file) can help to keep data management simple and consistent.

    On the other hand, you will have to update the entire OS (including the kernel) when you need to install a new release of the database - which means, that you'll have to reboot the machine.

    And - last but not least - the more code you have in the OS kernel, the higher is the probability of having dangerous bugs somewhere in the kernel.
    It should not be necessary to mention, that bugs in the OS kernel may compromise all system security.

    There are certainly many advantages and disadvantages regarding the database-filesystem issue, so I think it all depends on what you want to do with your computer.

    -----

    kind regards from Austria,
    octogen

    PS: i hope my english isn't too poor..
    And - by the way - even Microsoft uses AS/400 boxes for running its business, so what do you think, where did they get their inspiration from...?