Date: Wed, 9 Sep 2009 12:43:58 +0200 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Danny Carroll <fbsd@dannysplace.net> Cc: freebsd-fs@freebsd.org, Gerrit =?iso-8859-1?Q?K=FChn?= <gerrit@pmp.uni-hannover.de>, freebsd-stable@freebsd.org Subject: Re: zfs kernel panic Message-ID: <20090909104358.GG1901@garage.freebsd.pl> In-Reply-To: <4AA77834.1010007@dannysplace.net> References: <20090908172332.476d9e0b.gerrit@pmp.uni-hannover.de> <20090908164413.GC1539@garage.freebsd.pl> <20090909090715.9d8a58ef.gerrit@pmp.uni-hannover.de> <20090909083313.GA1901@garage.freebsd.pl> <4AA77834.1010007@dannysplace.net>
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[-- Attachment #1 --] On Wed, Sep 09, 2009 at 07:41:08PM +1000, Danny Carroll wrote: > On 9/09/2009 6:33 PM, Pawel Jakub Dawidek wrote: > >On Wed, Sep 09, 2009 at 09:07:15AM +0200, Gerrit Kühn wrote: > > > >>On Tue, 8 Sep 2009 18:44:13 +0200 Pawel Jakub Dawidek<pjd@FreeBSD.org> > >>wrote about Re: zfs kernel panic: > >> > >>PJD> If this is amd64, add vm.kmem_size="4G" to your loader.conf back. > >> > >>What about vm.kmem_size_max? Does that also need tuning? > >> > >No, this should be auto-tuned to some very large value. > > > > > Pawel (et al), > > Would it be possible for you to post to the list your ideas of a > complete set of tuning parameters for ZFS on amd64? I have used the > wiki article as a reference (http://wiki.freebsd.org/ZFSTuningGuide) but > it states that if you have > 2g ram and 7.2 then you do not need to tune > at all. I think that was the idea, although I see no reason to have less kernel address space than physical memory (except there might be other in-kernel variables auto-tuned based on kmem size). > I for one would be interested in learning a little more about how the > memory should be tuned. Specifically what might be interesting is to > know, once a parameter is set, is there an easy way to find out how it's > being used? i.e. If you start limiting the arc, is is possible to know > what sort of hit/miss rate you are getting. There are ARC statistics available here: # sysctl kstat.zfs -- Pawel Jakub Dawidek http://www.wheel.pl pjd@FreeBSD.org http://www.FreeBSD.org FreeBSD committer Am I Evil? Yes, I Am! [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFKp4buForvXbEpPzQRAoe2AKDFcQWjn0rVoeZSLczZmVM9BY5DEACg3whQ UK7cFH6qrKPIcHzdhAaRc7Q= =4+nt -----END PGP SIGNATURE-----
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