Subject: Re: the undocumented FFS2 root trouble
To: Matt Thomas <>
From: David Laight <>
List: tech-kern
Date: 05/01/2005 15:39:22
On Sun, May 01, 2005 at 05:56:15AM -0700, Matt Thomas wrote:
> David Laight wrote:
> > On Mon, Apr 25, 2005 at 08:56:57AM -0700, Jason Thorpe wrote:
> > 
> >>fsck is much faster on FFSv2, as well.
> > 
> > 
> > I think you mean newfs, fsck will be slower because the filesystem
> > metadata is twice the size.
> Not true.  fsck is faster since ffsv2 does not instantiate all the
> inodes during the newfs.  Instead, each cylinder grows their inode
> space as needed.  So there is usually less meta-data to check.

ok - so it has to do the sequential read through all the inodes.  I doubt
that is actually a major factor (if it is we should speed up sequential
reads from the raw disk device).

I have thought that it ought to be possible to speed up fsck by processing
directory and block-map sectors in sector order - thus avoiding disk seeks.


David Laight: