On Thu, 2002-09-26 at 17:39, Bruce Momjian wrote:
> Neil Conway wrote:
> > Greg Copeland <greg@CopelandConsulting.Net> writes:
> > > On Thu, 2002-09-26 at 16:03, Neil Conway wrote:
> > > > I'm not really familiar with the reasoning behind ext2's
> > > > reputation as recovering poorly from crashes; if we fsync a WAL
> > > > record to disk before we lose power, can't we recover reliably,
> > > > even with ext2?
> > >
> > > Well, I have experienced data loss from ext2 before. Also, recovery
> > > from crashes on large file systems take a very, very long time.
> >
> > Yes, but wouldn't you face exactly the same issues if you ran a
> > UFS-like filesystem in asynchronous mode? Albeit it's not the default,
> > but performance in synchronous mode is usually pretty poor.
>
> Yes, before UFS had soft updates, the synchronous nature of UFS made it
> slower than ext2, but now with soft updates, that performance difference
> is gone so you have two files systems, ext2 and ufs, similar peformance,
> but one is crash-safe and the other is not.
Note entirely true. ufs is both crash-safe and quick-rebootable. You
do need to fsck at some point, but not prior to mounting it. Any
corrupt blocks are empty, and are easy to avoid.
Someone just needs to implement a background fsck that will run on a
mounted filesystem.
-- Rod Taylor
