Craig Hammond wrote:
I am setting up a Samba fileserver on obsd 3.9-stable
I noticed that up until obsd3.3, in section 11 of the faq, it
recommended
increasing bufcachepercent for fileservers with lots of free memory.
Now there is no section 11 at all in the faq.
For a box that is basically only going to do Samba, is it still ok
to increase bufcachepercent to speed things up, and if so, are there
any limits I should be aware of? Obviously I wouldn't set it to 95%
but with 1 gb of RAM, is 50% ok.
did you read the commit message?
http://www.openbsd.org/cgi-bin/cvsweb/www/faq/faq11.html
See revision 1.50...
"Remove some bad stuff... NMBCLUSTERS gets people into
serious trouble, as does BUFCACHEPERCENT. Removed."
The problem with documenting knobs like that is people feel the need to
twist 'em. In the process, they demonstrate why OpenBSD developers set
things the way they are...though they rarely see the performance and
stability problems they caused as a direct result of their actions.
Rather, they whine that "OpenBSD doesn't work!" and waste a lot of
people's time until we eventually find out that little detail they
creatively left out.
THINK A MOMENT... If there was one magical setting which was Always
Best, don't you think that maybe the OpenBSD developers would have set
it there?
IF you want to twist knobs, start from the default, see if you can find
a real problem (note: if performance isn't absolutely as fast as need
be, that's not a problem if you are pulling one 100k file off the server
once a minute. It may be a problem if you are pulling those same files
many times a second). IF you spot a real problem, then twist just the
appropriate knobs, and see what happens. "Bigger" is not always better,
it isn't always even faster.
Nick.
