Re: memory strangeness (fwd)

On Fri, 5 Jul 2002, Gregor Mosheh wrote:

> I'm aware of the problems of over-allocating RAM, and I surely wouldn't
> want to force the buffers into swap. (thanks, Curt, for
> kern.ipc.shm_use_phys) On this particular system, though, it's doing
> nothing except PG. 384 MB of RAM, I can give PG 160 of it, which leaves me
> with some 170 MB of idle RAM.

No, that's not idle RAM; that's buffer cache. (FreeBSD, like most
modern Unix operating systems, will use any spare physical memory
to cache blocks read from the disk.) If you allocate 160/170, you
now have pretty much maximized your chances that postgres and the
operating system will be buffering the same data, and made your
memory as minimally effective as possible.

> I'd read somewhere (obiously outdated) that the MAXDSIZ was 128 MB. I've
> since rebooted with the kernel.GENERIC...  What's the sysctl setting I use
> to set/check the data size limits?

It's not a sysctl, because those limits are settable per-process.
Use "ulimit -aS" to check the current (soft) limits, and "ulimit
-aH" to check the hard limits (beyond which the soft limits may
not be raised). Also see the getrlimit manpage.

cjs
--
Curt Sampson  <cjs@cynic.net>   +81 90 7737 2974   http://www.netbsd.org
    Don't you know, in this new Dark Age, we're all light.  --XTC