Help test softupdates journaling (SUJ)
mav at FreeBSD.org
Sat Jan 9 09:53:09 UTC 2010
Jeff Roberson wrote:
> I have been augmenting softupdates with a small journal that will be
> processed in lieu of fsck in the event of a crash. I have written some
> about this project here: http://jeffr_tech.livejournal.com/
Sounds cool, but I have one question. Excuse my possible ignorance.
I was looking for BIO_FLUSH consumers and haven't found UFS there.
Unbacked write caching probably can make SoftUpdates unreliable, but it
is bearable while foreground fsck is used. As I understand, journaled
recovery is more dependent on data coherency, and so needs either
unbacked write caching to be disabled, or BIO_FLUSH to be used in
respective points by FS code. Am I right? So what's about BIO_FLUSH?
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