From owner-freebsd-questions@FreeBSD.ORG Sat Sep 11 15:47:06 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 1FAA8106566B for ; Sat, 11 Sep 2010 15:47:06 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id A5A778FC08 for ; Sat, 11 Sep 2010 15:47:05 +0000 (UTC) Received: by fxm4 with SMTP id 4so2794379fxm.13 for ; Sat, 11 Sep 2010 08:47:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=BcK1kLo/cHDDzgegepNwAMNxRC8LTIi2YNxogia5QTs=; b=CuCe/Ga223Rx6HXbP+AzHC51o+lTSzLVJ7zGv6eBhIQj5rnGLafs91R1mmtyRvO+Pl cWn58/cps92rKgN6Sq8InaHGVB6NEaJwRnshYi2uEAHJuVP10hdwBCZOUX8LVzZ/YS99 9WYgQ2Q3PTjC+cgj0jOCjdGz0XDfVPTgYy3NU= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=PxY1Q5GoSQNNHItZt8y5ckgsJuRCz/Km7NCjq3stOSJXYcsX3bmVIZP9i7clXitrKi k+mdWDu7qrRfCU3ls0t6x50M/i7AuDcJRxwmWTnwzmDk4NyUqTgjmel0F1Oo93gPee2H yq7aQNSfmwpd/iHQRqcNVb/msSMsAp7z7fguw= MIME-Version: 1.0 Received: by 10.223.122.196 with SMTP id m4mr1646391far.20.1284220023943; Sat, 11 Sep 2010 08:47:03 -0700 (PDT) Received: by 10.223.57.20 with HTTP; Sat, 11 Sep 2010 08:47:03 -0700 (PDT) In-Reply-To: <20100911152558.27153c31@gumby.homeunix.com> References: <20100911152558.27153c31@gumby.homeunix.com> Date: Sat, 11 Sep 2010 10:47:03 -0500 Message-ID: From: Adam Vande More To: RW Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-questions@freebsd.org Subject: Re: gjournal+geli X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Sep 2010 15:47:06 -0000 On Sat, Sep 11, 2010 at 9:25 AM, RW wrote: > > I'm planning to use gjournal+geli on a 2TB drive in a USB enclosure. > > What I've read about this suggest that the order should be: > geli-gjournal-ufs. I was wondering if it's possible to do it in > the order gjournal-geli-ufs, which should be much more efficient. I've > read that ufs should go directly on gjournal, but I just wanted to > check that that is needed. > > I was also wondering about the journal size, and whether there are any > performance optimizations to be made to mitigate the extra > encryption/decryption in the journal. The man page suggests a size of at > least 2xmemory which would be 2x1.5GB now, or maybe 2x16GB to allow for > potential upgrades. It seems very large. The disk will hold fairly > static data so it will be mostly be long sustained writes as files are > copied in. Currently coping from geli to geli with soft-updates is > slightly cpu limited. > AFAIK, ufs must be on top of gjournal. Specific changes were made to allow ufs to be aware of the journal and I think sticking geli in-between would destroy that relationship. IME, gjournal is more sensitive to load as the man page also suggests. I have one production server with moderate load, and a 5 GB problem. I think something like 5 -10 GB journal would be more than enough for almost all loads, but that's just a guess. It's easy to test though, just run blogbench or some other io benchmark for a sustained period of time. If it doesn't panic, you're golden. -- Adam Vande More