Re: HEADS UP: UFS2 now the default creation type on 5.0-CURRENT

From: Robert Watson <rwatson_at_freebsd.org>
Date: Tue, 22 Apr 2003 10:52:22 -0400 (EDT)
On Tue, 22 Apr 2003, Wilkinson,Alex wrote:

> Can you recommend any papers that explain the differences between UFS1
> and UFS2 ie the benefits ? 

I don't believe there's a specific paper at this point, although no doubt
there will be.  The upshots are:

o 64-bit pointers up the wazoo
o Layout and functional changes to help support variable-size blocks
  (extent-like allocation) 
o Extension of various flag fields
o Addition of per-inode extended attribute extent
o Lazy inode initialization (watch newfs(8) fly)

The motivating factor in the layout change was the need for better EA
support, and while we were at it we figured we'd do a bunch of other
useful things too.  UFS2 uses the same basic technologies as modern UFS1
(inodes, linear directory layout, soft updates, snapshotting, background
file system checking, etc) so it was a relatively low-risk change.

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert_at_fledge.watson.org      Network Associates Laboratories
Received on Tue Apr 22 2003 - 05:52:12 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:37:04 UTC