lkml.org 
[lkml]   [2006]   [Aug]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: the " 'official' point of view" expressed by kernelnewbies.org regarding reiser4 inclusion
    Hans Reiser wrote:
    > Edward Shishkin wrote:
    >
    >
    >>Matthias Andree wrote:
    >>
    >>
    >>>On Tue, 01 Aug 2006, Hans Reiser wrote:
    >>>
    >>>
    >>>
    >>>>You will want to try our compression plugin, it has an ecc for every
    >>>>64k....
    >>>
    >>>
    >>>
    >>>What kind of forward error correction would that be,
    >>
    >>
    >>
    >>Actually we use checksums, not ECC. If checksum is wrong, then run
    >>fsck - it will remove the whole disk cluster, that represent 64K of
    >>data.
    >
    >
    > How about we switch to ecc, which would help with bit rot not sector loss?

    Interesting aspect.

    Yes, we can implement ECC as a special crypto transform that inflates
    data. As I mentioned earlier, it is possible via translation of key
    offsets with scale factor > 1.

    Of course, it is better then nothing, but anyway meta-data remains
    ecc-unprotected, and, hence, robustness is not increased..

    Edward.

    >
    >>
    >> and how much and
    >>
    >>
    >>>what failure patterns can it correct? URL suffices.
    >>>
    >>
    >>Checksum is checked before unsafe decompression (when trying to
    >>decompress incorrect data can lead to fatal things). It can be
    >>broken because of many reasons. The main one is tree corruption
    >>(for example, when disk cluster became incomplete - ECC can not
    >>help here). Perhaps such checksumming is also useful for other
    >>things, I didnt classify the patterns..
    >>
    >>Edward.
    >>
    >>
    >
    >
    >
    >

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-08-04 19:07    [W:0.037 / U:31.460 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site