From owner-freebsd-current@FreeBSD.ORG  Sun Dec 16 20:09:54 2007
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id D9A4C16A420
	for <freebsd-current@freebsd.org>; Sun, 16 Dec 2007 20:09:54 +0000 (UTC)
	(envelope-from matt@layeredtech.com)
Received: from mail.layeredtech.com (mail.layeredtech.com [216.39.90.80])
	by mx1.freebsd.org (Postfix) with ESMTP id 78EE113C4E9
	for <freebsd-current@freebsd.org>; Sun, 16 Dec 2007 20:09:54 +0000 (UTC)
	(envelope-from matt@layeredtech.com)
Received: (qmail 49121 invoked by uid 80); 16 Dec 2007 19:51:15 -0000
Received: from 76.209.125.244
	(SquirrelMail authenticated user matt@layeredtech.com)
	by mail.layeredtech.com with HTTP;
	Sun, 16 Dec 2007 13:51:15 -0600 (CST)
Message-ID: <42042.76.209.125.244.1197834675.squirrel@mail.layeredtech.com>
In-Reply-To: <86r6hmsnew.fsf@ds4.des.no>
References: <47606C09.2070209@isc.org> <47609F0A.7010805@clearchain.com>
	<47609FE3.8040606@barafranca.com> <4760B444.1080604@clearchain.com>
	<06CAC7FC-DB58-441D-A6E0-76D1D8133393@tamu.edu>
	<86ir31xwlu.fsf@ds4.des.no>
	<ADCCD5E6-A792-49B9-A346-753176C12F2E@tamu.edu>
	<fjuljp$cvb$1@ger.gmane.org> <476343B4.8080208@FreeBSD.org>
	<fk09p8$b16$1@ger.gmane.org> <86tzmk54tt.fsf@ds4.des.no>
	<fk0ue7$bp$1@ger.gmane.org> <86r6hmsnew.fsf@ds4.des.no>
Date: Sun, 16 Dec 2007 13:51:15 -0600 (CST)
From: matt@layeredtech.com
To: freebsd-current@freebsd.org
User-Agent: SquirrelMail/1.4.5
MIME-Version: 1.0
Content-Type: text/plain;charset=iso-8859-1
Content-Transfer-Encoding: 8bit
X-Priority: 3 (Normal)
Importance: Normal
Subject: Re: ZFS melting under postgres...
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 16 Dec 2007 20:09:54 -0000

> Ivan Voras <ivoras@freebsd.org> writes:
>> These are all "normal" CompactFlash cards, for which the widely
>> available size seems to be 16 GB max, right?
>
> So?  That's more than enough for a ZFS intent log (as a rule of thumb,
> the ZIL should be half the size of the server's RAM).
>
>> Did you (or anyone) deploy CF drives for production servers?
>
> My router (and DNS, NTP and DHCP server) is a net4801 with a 1 GB CF
> chip.
>
> DES

Some folks are fond of having a fast boot disk with practically no latency
and no moving parts.

I run quite a few production servers on CF drives in a very large (12k+
servers) data center environment. In nearly every case, the CF card is the
systems root (/) partition and is always mounted read-only.

In some cases where we use CF, the systems also have a SAS/SATA disk for
maintenance. When needed, we can spin up the SAS/SATA disk. On that hard
drive, we keep a history of the CF card images and other maintenance items
like /usr/ports and /usr/src.

We use ATA CF adapters that I buy off eBay for $1.98 each. They ship
direct from Hong Kong and work great.