Re: FAQ material I think (was: Performance question)

On Thu, 17 Jun 1999, Clifton Royston wrote:

> Jason Haar writes:
> > On Thu, Jun 17, 1999 at 01:13:53PM -0700, Mike Batchelor wrote:
> > > On Solaris, the kernel variable for the directory name lookup cache size is
> > > 'ncsize'. In /etc/system, you might want to try 'set ncsize = 8192' or even
> > > higher. The kernel variable 'ufs_inode' - which is the size of the inode
> >
> > [Other good stuff about Solaris and *BSD tweaks deleted]
> >
> > I think this stuff should be documented in the FAQ - it's really useful for
> > big sites...
>
> Hear hear. A performance recommendations section would be great. I'd
> also like to see it documented there that the noatime mount option is
> safe to use on systems which support it; I wasn't sure at first whether
> I could turn it on or if Squid looked at file creation times, though
> since others use it (e.g. the benchmark stats) I assume it's safe.
>
> FYI, BSD/OS 4.0 supports the soft-updates file system option previously
> mentioned. I haven't tried to do any benchmarks yet, though, so I
> can't say how much effect it has.

A colleague ran benchmarks on the BSD/OS soft-updates and the performance
improvement was considerable. I can't find where I stashed his results so
may have deleted them. He did find an error condition that BSDi promptly
fixed and included in the BSD/OS 4.0.1 updates.

By default, all our systems are now configured with soft-updates enabled.
The biggest performance improvements have occurred on systems that create a
lot of temporary files. With soft-updates, these are seldom, if ever,
written to disk. One system running MRTG and Squid used to report a load
average in the 3 to 4 range rather consistently. Top now reports a load
average in the .5 to 1.5 range.

Merton Campbell Crockett
Received on Fri Jun 18 1999 - 00:31:07 MDT