Is the fsync() fake on FreeBSD6.1?

David Xu davidxu at
Mon Jul 3 00:43:11 UTC 2006

On Tuesday 27 June 2006 11:34, Greg 'groggy' Lehey wrote:

> This is not the case for Linux, where fsync syncs the entire file
> system.  That could explain some of the performance difference, but
> not all of it.  I suppose it's worth noting that, in general, people
> report much better performance with MySQL on Linux than on FreeBSD.

I recent have tested SCHED_CORE, the scheduler has same dynamic
priority algorithm as Linux 2.6, it can make 10% performance boost
for super-smack on my dual PIII, I tested it on local host,  but 
its user interaction is quite bad under heavy load,  scheduling
alogrithm makes sense, but 4BSD is still best scheduler for me.

> > I mean than the data is only written to the drives memory and so can
> > be lost if power goes down.
> I don't believe that fsync is required to flush the drive buffers.  It
> would be nice to have a function that did, though.
> > And how I can confirm this?
> Trial and error?
> Greg
> --
> See complete headers for address and phone numbers.

More information about the freebsd-performance mailing list