From owner-freebsd-hackers@FreeBSD.ORG Thu Jan 19 06:59:38 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A046B16A41F for ; Thu, 19 Jan 2006 06:59:38 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.FreeBSD.org (Postfix) with ESMTP id 565D043D48 for ; Thu, 19 Jan 2006 06:59:38 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from obsecurity.dyndns.org (elvis.mu.org [192.203.228.196]) by elvis.mu.org (Postfix) with ESMTP id 350391A3C1B; Wed, 18 Jan 2006 22:59:38 -0800 (PST) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 8840D5125B; Thu, 19 Jan 2006 01:59:37 -0500 (EST) Date: Thu, 19 Jan 2006 01:59:37 -0500 From: Kris Kennaway To: Ensel Sharon Message-ID: <20060119065937.GA65484@xor.obsecurity.org> References: <20060118201941.GA48904@xor.obsecurity.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="yrj/dFKFPuw6o+aM" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Cc: freebsd-hackers@freebsd.org, Kris Kennaway Subject: Re: tuning to run large (1000+) numbers of null_mounts X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Jan 2006 06:59:38 -0000 --yrj/dFKFPuw6o+aM Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jan 19, 2006 at 01:55:22AM -0500, Ensel Sharon wrote: >=20 >=20 > On Wed, 18 Jan 2006, Kris Kennaway wrote: >=20 > > > hmmm...the cut and paste of that loud warning was from a 6.0-RELEASE = man > > > page ... if I need to be CURRENT to get the updated man page, do I al= so > > > need to be CURRENT to get the safe null_mount code itself ? > > >=20 > > > Or is 6.0-RELEASE safe ? (re: null_mount) > > >=20 > > > Thanks a lot. > >=20 > > 6.0-RELEASE is also safe. I only just removed the warning the other > > day, but I'll also be merging it to 6.0-STABLE. >=20 >=20 > Ok, that is good to know. >=20 > However, I continue to see instability on this system with the 2000+ > null_mounts. Are there any system tunables / sysctls / kernel > configurations that I should be studying or experimenting with that are > relevant to this ? >=20 > Perhaps looking more broadly, are there any tunables related to large > numbers of mounted filesystems _period_, not just null mounts ? Not that I know of. You'll need to proceed down the debugging route I mentioned. > For what it is worth, the system also has several mdconfig'd and mounted > snapshots (more than 5, less than 10). Further, all of the null mounts > mount space from within a mounted snapshot into normal filesystem space. = =20 > With all the snapshots mounted and all the null mounts mounted, I find > that commencing an rsync from the filesystem that all these exist on locks > up the machine. I can still ping it, but it refuses all connections. It > requires a power cycle. >=20 > Comments ? Snapshots are a much more likely cause of system instability than nullfs mounts, IMO. Kris --yrj/dFKFPuw6o+aM Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFDzzjYWry0BWjoQKURAtMzAJ9EtHfIfYy1/adjxzrT04pXciehyQCg9UtG 1SZlrtqyHfgQw5t4jl6CGq4= =90zd -----END PGP SIGNATURE----- --yrj/dFKFPuw6o+aM--