Background fsck

[Jeroen C. van Gelderen]

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