From owner-freebsd-questions@FreeBSD.ORG Fri Jun 1 15:26:23 2012 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0376D106567C for ; Fri, 1 Jun 2012 15:26:23 +0000 (UTC) (envelope-from kudzu@tenebras.com) Received: from mail-pb0-f54.google.com (mail-pb0-f54.google.com [209.85.160.54]) by mx1.freebsd.org (Postfix) with ESMTP id C2EF68FC18 for ; Fri, 1 Jun 2012 15:26:22 +0000 (UTC) Received: by pbbro2 with SMTP id ro2so3345117pbb.13 for ; Fri, 01 Jun 2012 08:26:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:x-gm-message-state; bh=lj9Hco1WIW4VgZXK9hi8zx2FzHHlXOaxbCq8g+eNkkA=; b=aArmTT2j150tpNVf4O0OJQ3jzTHWUAYUpAt1BSxUYC9wGo92gtXGzY6QcxCOz8ZLB8 0z2tojABX1FWDXJ1sW8fFXD8TB2IrlOIw+PCpeJjYC8KE2fN3qtUF6H+NPpMiDBb+KDW zMShZBpj7R5RNI8AJbVW+4/9QSKOoSkctSxVDuNnU8XvWVNI5LcBlVjRBy6LbHOZ8odU FFxyr/Ui2lkabsQVaMDQijFtlr2ZEftJw7Z9OhrUwsAB/jdOLbQpeXAN2f+GDL0Xp9YW 9leLRTn+r0QjtkTrZXHOiZFlbTH0csgTwiruI6KoHlyP6KhaHYxjUDSRW+Oq2Vr0TXCg vJKA== MIME-Version: 1.0 Received: by 10.68.136.65 with SMTP id py1mr11090103pbb.81.1338564382349; Fri, 01 Jun 2012 08:26:22 -0700 (PDT) Received: by 10.68.202.8 with HTTP; Fri, 1 Jun 2012 08:26:22 -0700 (PDT) In-Reply-To: References: <20120601163520.f130cdcd.freebsd@edvax.de> Date: Fri, 1 Jun 2012 08:26:22 -0700 Message-ID: From: Michael Sierchio To: Wojciech Puchar Content-Type: text/plain; charset=ISO-8859-1 X-Gm-Message-State: ALoCoQnC+DHvAlU+t+9WgJUrLZlk386Z8u1XqdE5B1i5cszrVXLqe7HbVpEoMoIf/qQTaU3VtDtR Cc: Kaya Saman , Polytropon , freebsd-questions@freebsd.org Subject: Re: Anyone using freebsd ZFS for large storage servers? 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: Fri, 01 Jun 2012 15:26:23 -0000 On Fri, Jun 1, 2012 at 8:08 AM, Wojciech Puchar wrote: > ZFS is somehow in that part similar to Amiga "Fast" File System. when you > overwrite a directory block (by hardware fault for example), everything > below that directory will disappear. You may not be even aware of it until > you need that data > > Only separate software (that - contrary to ZFS - do exist) can recover > things by linearly scanning whole disk. terribly slow but at least possible. > > > > EVEN FAT16/FAT32 IS MORE SAFE. First of all, in any environment you expect disk failures. Which operationally means replacing the entire disk. Then you rely on the raid recovery mechanism (in whichever flavor of disk discipline you choose). ZFS semantics (copy on write, for example) are much safer than UFS semantics. This is not to say that UFS is not a more mature and possibly robust filesystem. But relying on gmirror, graid, etc. means you are no longer relying solely on the robustness of the underlying filesystem - you cannot offer a reduction proof that shows that if gmirror is bad, it means UFS is bad. I use UFS for most purposes, but would never build a large fileserver using gmirror on UFS. Your assertions about the dangers of ZFS are just that - assertions. They are not borne out in reality. - M