Re: Background fsck

["Jeroen C. van Gelderen" <jeroen@xxxxxxxxxxxxxxx>]

Dan Melomedman wrote:

> Matthew Dillon wrote:
>
> > :Hi all,
> > :this is the outline of how to implement a background fsck for DragonFly.
> > :DR, this is somewhat more mature than what I wrote on Friday.
> > :
> > :Joerg
> >
> > :The first alternative is using a journal for all meta-data updates. That's
> > :what most Linux filesystems are doing. The advantage is almost no time
> > :needed to bring a uncleanly unmounted filesystem back into a working state.
> > :The disadvantage is a steady slow down for _all_ meta-data updates.
> >
> >    This actually doesn't slow down meta-data updates all that much,
> >    because the journal is linear it takes only one seek to update while
> >    you might need hundreds of seeks to update the meta-data in its 
> >    individual locations on the disk.
> >
> >    This is really the best way to do it, I think.
>
>
> I've read somewhere that it can actually speed some specific cases up.

Perhaps of interest in this regard:

Jonathan S. Shapiro, Jonathan Adams
"Design Evolution of the EROS Single-Level Store"
http://www.eros-os.org/papers/storedesign2002.pdf

Cheers,
-JC