Journaled filesystem not suitable for large filesystems?

Discussion in 'Mac OS X 10.3 (Panther) Discussion' started by cb911, Mar 8, 2004.

  1. cb911 macrumors 601

    cb911

    Joined:
    Mar 12, 2002
    Location:
    BrisVegas, Australia
    #1
    i was just reading up on Gentoo (going to install Getnoo 2004.0!! :D) and came accross a bit of info about ext3 (the journaled version of the linux filesystem):

    i was just wondering if this info about journaled filesystems applies to Panther and the way it handles journaling... i've never liked the journaling in Panther for some reason.

    does anyone know if you had a G5 with a 250GB HD (single partiton with 10.3 installed) and journaling enabled, would that effect the performance?
     
  2. Felix_the_Mac macrumors member

    Joined:
    Aug 18, 2003
    Location:
    UK
    #2
    Journalled file systems are intended for large filesystems.
    They became necessary since doing an fsck (file system check) on a large modern disk can take hours whereas a jfs will take literally seconds.

    The specific performance characteristics of any particular jfs implementation will differ, so the fact that EXT3 is said to be sub-optimal is not necessarily true of HFS+.

    I don't know much more than that but I expect that if you google "journalled file systems HFS+ speed" etc etc. you could find some benchmarks.
     
  3. Flynnstone macrumors 65816

    Flynnstone

    Joined:
    Feb 25, 2003
    Location:
    Cold beer land
    #3
    ext3 and ext2 are then same file system, ext2. What ext3 does is add journaling to ext2. A very simplistic look at journaling is this, a program via the filesystem is going to make a change to a file, so it writes to the journal what its about to do, then changes the file, then removes the entry in the journal.
    So returning from my little tangent, it is said that ext2 doesn't scale well. So this implies ext3 doesn't scale well. So ext3 not scaling well is not specifically due to the journalling.
    There have been some benchmark testing of ext3 and ext2 filesystems. It would seem logical that ext2 is faster than ext3 due to the extra journalling action of ext3. But ... there are cases where ext3 is faster than ext2.

    But I think it is safe to say that ext3 is inheritantly "safer" than ext2, ie your data better protected.
    Now HFS+ vs ext2 vs ext3 ... I don't know that answer, but in my opinion, journalling is better.
     
  4. superbovine macrumors 68030

    superbovine

    Joined:
    Nov 7, 2003
  5. cb911 thread starter macrumors 601

    cb911

    Joined:
    Mar 12, 2002
    Location:
    BrisVegas, Australia
    #5
    okay, i understand it now. :) didn't think about the differences between ext2/ext3 and HFS+. ;)

    i remember reading all about the way Panther uses journaling just to prove to myself that it wasn't going to stuff everything up. but i always forget about the details. maybe i do need a refresher. :p
     

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