gjournal and Softupdates

Christian Laursen xi at borderworlds.dk
Tue Sep 12 04:26:37 PDT 2006


Ivan Voras <ivoras at fer.hr> writes:

> Christian Laursen wrote:
>> Ivan Voras <ivoras at fer.hr> writes:
>>
>>> - todays desktop drives can lie about writing data. SoftUpdates relies
>>> on some assumptions about when the data is physically written to
>>> media, and those are not always valid today
>>
>> I think journaling relies on the same assumptions.
>
> Doesn't it rely less since a journal is written sequentially, but SU
> expects ordering of many writes to different parts of the file system
> to be persistent and in sequence?

Journaling also needs writes to be done in the correct order. You don't
want to write the real update to the filesystem before you have made sure
that it has been committed to the journal. If that can happen you are no
better off than without the journal.

-- 
Christian Laursen


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