Subject: Re: wd, disk write cache, sync cache, and softdep.
To: J Chapman Flack <>
From: Charles M. Hannum <>
List: tech-kern
Date: 12/16/2004 23:36:46
On Thursday 16 December 2004 23:14, J Chapman Flack wrote:
> > rather have excellent performance.  Large systems have backup power and
> > backups.  They're not concerned with this level of nit-picking.
> So how does the admin proceed after the failed power supply has been
> replaced, the filesystems preened and restored, the last DBMS checkpoint
> restored from backup and then rolled forward to point of failure from the
> journal, the system put back on line, and the phone begins to ring about
> some of Judge Smith's cases appearing to have the wrong defendants?

That's a strawman.

The fact is, there's no point in designing one component for five 9s 
reliability when there are other components that, to be quite blunt, are 
barely getting two 9s.  And that is what's going on here.  If you look at the 
high level picture, you'll see that there are better ways to solve the global 
system problems than applying a hack to this specific place.