This is what makes RPM slow as well [LWN.net]

This is what makes RPM slow as well

Posted May 26, 2008 17:19 UTC (Mon) by lmb (subscriber, #39048)
In reply to: This is what makes RPM slow as well by arjan
Parent article: Fsyncers and curveballs (the Firefox 3 fsync() problem)

I've had a crazy idea here a few weeks ago. If you look at OCFS2, you can see that modern
filesystems can have more than one journal and coordinate across them. (Even if they might be
merged into a single journal space on disk, logically it could be several.)

You could then have processes join transaction groups - as long as the transactions happen in
unrelated areas of the filesystem, there'd be no need for coordination, and performance would
improve.

Some refinement is needed, but single journal really is sooo 1999 ;-)

This is what makes RPM slow as well

Posted Jun 1, 2008 22:19 UTC (Sun) by jlokier (guest, #52227) [Link]

Trees and cascades of multiple journals go naturally together.  See btrfs, logfs, ubifs, zfs,
reiser4...  After a while it stops looking like a journal.  But all the tricks to make a high
performance and reliable journal with async barriers can apply to a tree as well.