From owner-freebsd-fs@FreeBSD.ORG Wed Dec 30 05:18:37 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 37CF71065672 for ; Wed, 30 Dec 2009 05:18:37 +0000 (UTC) (envelope-from benschumacher@gmail.com) Received: from mail-pz0-f185.google.com (mail-pz0-f185.google.com [209.85.222.185]) by mx1.freebsd.org (Postfix) with ESMTP id 095FF8FC12 for ; Wed, 30 Dec 2009 05:18:36 +0000 (UTC) Received: by pzk15 with SMTP id 15so8044530pzk.3 for ; Tue, 29 Dec 2009 21:18:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to:cc :content-type:content-transfer-encoding; bh=gQqGNCfO+30ZdiPAL4P8kov+Ef8C52nBCiQhoy/+ZLc=; b=gEX6r7GxfaEjr8zoEgdWrwJWcpUP16Ayq88w81z2SA8kylFTTUvE3ASH1r/qJWy82a EUmGA3wHR+coMqVLF5c5Jn+5DqYuvPjEIrpOq0N579WQ4tCUt9Pbg6x1H607pZojtVh6 mXz/pyy8IDHmBWj7yRxv6Ui/pj1dUSIE8nhRg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=qQ8xiyU7hRrNOcORj2kS5HzpepMAyvD36KkyBCbiFDhBYBb9Z5+ngj1VRlPqVGCQAs 8cAZT6L9C+ICZTLBM9+wGWOVl95SPEo5sKmJfJ/1caIVFGRaj8uyiwm56IgMkenSo5l7 hHEbhVZj7UpUyfZJz0fpoiXgsCRDsXjHKE+kQ= MIME-Version: 1.0 Sender: benschumacher@gmail.com Received: by 10.143.25.29 with SMTP id c29mr11967259wfj.255.1262150309670; Tue, 29 Dec 2009 21:18:29 -0800 (PST) In-Reply-To: References: <32CA2B73-3412-49DD-9401-4773CC73BED0@patpro.net> <4B3283F2.7060804@barryp.org> <3ea87f5f62bb8ba30d798d4605a64c83@localhost> Date: Tue, 29 Dec 2009 22:18:29 -0700 X-Google-Sender-Auth: a94100bdc8d34bfc Message-ID: <9859143f0912292118h44a33961mc8207d9b943a5f1f@mail.gmail.com> From: Ben Schumacher To: freebsd-fs@freebsd.org Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Jeff Roberson Subject: Re: snapshot implementation X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Dec 2009 05:18:37 -0000 On Sun, Dec 27, 2009 at 6:25 PM, Jeff Roberson wr= ote: > It can take some time depending on fs activity on the machine. =C2=A0Ther= e are > ways to continue to optimize it within the existing infrastructure. =C2= =A0It only > requires someone willing to expend the time. Any idea how complex of a task this is (and how much fruit it would bear)? I've been interested in dipping my toes into some FreeBSD kernel work, but I'm not exactly sure where to start. I honestly don't have tons of free time to work on it (job commitments and all that), but am curious if this is something that an experienced C programmer would have a shot at doing having very little experience with low-level kernel internals. (I'm used to dealing with POSIX interfaces and not the code that implements them...) I've recently picked up a copy of "The Design and Implementation of the FreeBSD OS", so I'm starting there, but I would love it if anybody could toss me a hint or two on what some of the low-hanging fruit in the arena might be. I've been playing with ZFS on a few boxes now, but I've had (even with FreeBSD 8) enough unusual crashes that I'm personally not ready to commit to using it on at least one "mission critical" project I'm working on. That being said I'd love to be able to do snapshots on the box without it hanging for over an hour due to the fact that the data drive is >400GB (frankly on the small side for some of the storage applications I've read about on this mailing list). Any hints, tips, pointers would be appreciated. Cheers, Ben