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    SubjectRe: mode data=journal in ext3. Is it safe to use?
    Hello!

    On Fri, Jun 18, 2004 at 11:41:23AM +0200, Helge Hafting wrote:

    > >If you can reproduce a garbage in files in ordered journal mode, that
    > >would be a
    > >bug that should be fixed then.
    > Hard to _produce_, but consider:
    > 1. Write data to an existing file
    > 2. Sync metadata
    > 3. data is forced out because of ordered mode, a powerout crash happens
    > in the middle of this. The file now has a block with a mix of new
    > and old,

    Well, this is not much worse than having two blocks, one from old file
    and one from new after a crash.

    > it may even be unreadable due to a bad sector checksum.

    Well, in data journaled mode you may get unreadable journal, is this much
    better? (Also original question was about CF flash media, so no bad sector
    problems I presume).

    > With data journalling you either get the old data (because the crash
    > happened
    > during a write to the journal) or new data (crash happened during data
    > write,

    Well, while with data journaling mode your granularity is one block,
    with data ordered it is one sector.

    > the data is restored from the good copy in the journal.)

    Bye,
    Oleg
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