On Fri, 28 Apr 2000, Larry McVoy wrote:
> On Sat, Apr 29, 2000 at 11:37:34AM +0900, GOTO Masanori wrote:
> > I don't know quantitative comparison between FreeBSD FFS
> > and Ext2. However, both FFS and ext2 have similar
> > structures, so I guess both performance are nice...
>
> UFS is a lot slower than ext2 because ext2 does async meta data updates. This
> has been the cause of much discussion, with the UFS crowd (I'm one of them,
> I doubled UFS performance at Sun) claiming that because UFS is "safe" and
> ext2 is "unsafe". That claim is where I part ways with the UFS crowd, I've
> been using ext2 for years, have survived many crashes, and I don't see any
> difference in the frequency of fsck problems.
>
> And the difference in performance is HUGE. A file create in UFS is about
> 12,000 usecs. A create in in ext2 is about 100 usecs.
Larry, that's only a part of the story. First of all, UFS on Linux is
async by default, just as ext2. So speed is about the same. Said that,
Linux UFS driver is, IMO, less reliable than ext2 one.
And on FreeBSD... You have to compare not sync/async, but
soft-updates/async. And there the difference is nowhere near 120:1...
I would not trust ext2 driver in FreeBSD too much - it's based on the
old code and we had found data-corrupting races on our side since then.
And it's not too actively maintained.
