Date: Fri, 10 Apr 2009 17:03:56 +0100 From: Matthew Seaman <m.seaman@infracaninophile.co.uk> To: ipfreak@yahoo.com Cc: freebsd general questions <freebsd-questions@freebsd.org> Subject: Re: loader.conf Message-ID: <49DF6DEC.7010706@infracaninophile.co.uk> In-Reply-To: <493958.16188.qm@web52105.mail.re2.yahoo.com> References: <493958.16188.qm@web52105.mail.re2.yahoo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--------------enig66962C36A63CBDF8D19A8564
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: quoted-printable
gahn wrote:
> Hi all:
>=20
> I have a machine with 2GB memory. in the file loader.conf, there is a l=
ine:
>=20
> #hw.physmem=3D"1G" # Limit physical memory. See loader(8=
)
>=20
> Could I remove the "#" and change that to "2G"?
>=20
> Interestingly, the sysctl indicates the parameter of "hw.physmem" is no=
t changeable.
>=20
> Any guru here give me some enlightenment?
hw.physmem is a loader tunable: ie. you can only set it from the boot
loader before the kernel is fully operational. Once the kernel is runnin=
g
it can't be altered.
hw.physmem is designed to let you test running a kernel with less RAM
than is physically installed in a machine. Not having to pop the case
and physically pull memory sticks out can be pretty useful. It's not of
general interest -- only for kernel and various other software developers=
in the main -- as the usual thing is to make use of all the RAM you have
available or (in the case of 32bit machines) that the system is capable o=
f
addressing.=20
If hw.physmem is unset in loader.conf the kernel will automatically use a=
ll
the memory available to it: this is the correct and desirable behaviour f=
or
the vast majority of systems. For a 2GB machine, that means the system w=
ill
use all the RAM that's installed.
Cheers,
Matthew
--=20
Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard
Flat 3
PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate
Kent, CT11 9PW
--------------enig66962C36A63CBDF8D19A8564
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.11 (FreeBSD)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iEYEAREIAAYFAknfbfMACgkQ8Mjk52CukIy2WgCdGL2DQfWPCUp8e33Q5solxELS
luAAn1MMAOCl6D9Tqvq/Gswqt43jAtGv
=XrEX
-----END PGP SIGNATURE-----
--------------enig66962C36A63CBDF8D19A8564--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?49DF6DEC.7010706>