[call for helpers!] Tuning for the Beaver Challenge

[Andrew J Caines]

For your consideration, bearing in mind I haven't read all details of the
challenge or the systems and therefore may suggest inappropriate, wrong or
dangerous things:

Custom kernel enabling only the hardware needed, all compiled in (no
modules), but be careful with fancy looking options in LINT/NOTES. It may
be prudent to hard code interrupts, flags and other parameters to avoid
potential suboptimal automatic allocations (eg. all PCI devs on irq 9).

Mount all filesystems with async, noatime and *enable softupdates*.

Use carefully sized (ie. just big enough) mfs filesystems for any area
with dynamically generated data such as temporary files, server
scoreboards, etc. /tmp and /var/run, at least.

If there's a foo_enable="NO" you put in rc.conf, then do so.

Disable as much logging as possible at system and application level, at
source or config or by logging to /dev/null. If you have to log, trim I/O
to the minimum, maximise buffering and minimise overhead (eg. "-n" for
syslog).

If any DNS activity is needed, a local cache (eg. dnscache) can help, but
so can a nicely populated /etc/hosts. Depending on the tests, it may be a
good idea to have the hostname (fully and unqualified) associated with the
loopback rather than the (primary) network interface.

For the Java benchmarks, try all the implementations which work, including
the emulated ones.

If the storage is going to be striped over all five disks in hardware by
the controller, then notion of putting data "on the outside of the disk"
doesn't apply. In fact in this configuration it _may_ make sense to use
one big filesystem and leave it to the OS to optimise the filesystem I/O.


-Andrew-
-- 
 _______________________________________________________________________
| -Andrew J. Caines-   Unix Systems Engineer   A.J.Caines at halplant.com  |
| "They that can give up essential liberty to obtain a little temporary |
|  safety deserve neither liberty nor safety" - Benjamin Franklin, 1759 |