Date: Wed, 22 Apr 2009 14:16:06 +0200 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-fs@freebsd.org Subject: Re: FreeBSD 7.2-RC1 - ZFS related kernel panic "kmem_map too small" Message-ID: <gsn1q2$51b$1@ger.gmane.org> In-Reply-To: <20090422123020.42b756c1@ernst.jennejohn.org> References: <49EE49D8.7000902@free.de> <20090422123020.42b756c1@ernst.jennejohn.org>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig07E2043828666B905F83E9AB Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Gary Jennejohn wrote: > On Wed, 22 Apr 2009 00:34:00 +0200 > Kai Gallasch <gallasch@free.de> wrote: >=20 > [snip a lot of stuff] >> In /usr/src/UPDATING I read: >> >> [..] >> >> 20090207: >> ZFS users on amd64 machines with 4GB or more of RAM should >> reevaluate their need for setting vm.kmem_size_max and >> vm.kmem_size manually. In fact, after recent changes to the >> kernel, the default value of vm.kmem_size is larger than the >> suggested manual setting in most ZFS/FreeBSD tuning guides. >> >> So I understood this as "vm.kmem_size is set unnecessary large by >> default. You should think about decreasing it to save some RAM" >> >> On my amd64 server the default values of kmem_size are >> >> vm.kmem_size_scale: 3 >> vm.kmem_size_max: 3865468109 >> vm.kmem_size_min: 0 >> vm.kmem_size: 1201446912 >> >> Can someone give me a hint how to debug this problem further, or how t= o >> find some reasonable values for setting vm.kmem_size_max and >> vm.kmem_size with 16G of RAM? >> >=20 > Hmm, I wonder whether this applies to 7.2-RC1. I don't know whether > the kernel changes have been committed to 7.2 or whether they were > already present when we started work on 7.2 because I haven't been > paying much attention. 7.2 was branched last Friday - quick browsing of commit messages doesn't find any relevant new development between Friday and now. > On my 8-current amd64 machine with only 4GB of RAM I see larger values > than you see with 16GB: >=20 > sysctl vm.kmem_size_max > vm.kmem_size_max: 4509713203 > sysctl vm.kmem_size > vm.kmem_size: 1335824384 Ok, but remember that ZFS in -CURRENT is very different from ZFS in -STAB= LE. --------------enig07E2043828666B905F83E9AB Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFJ7wqGldnAQVacBcgRAijhAKD3ET5uLbJ1UXaWHeohoWYa6V4WOgCgu2pS ecpjDMvuSi5Z47w2v15d34o= =2XQI -----END PGP SIGNATURE----- --------------enig07E2043828666B905F83E9AB--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?gsn1q2$51b$1>