From owner-freebsd-questions@FreeBSD.ORG Fri Jun 1 15:08:09 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 4688E106566B for ; Fri, 1 Jun 2012 15:08:09 +0000 (UTC) (envelope-from wojtek@wojtek.tensor.gdynia.pl) Received: from wojtek.tensor.gdynia.pl (wojtek.tensor.gdynia.pl [89.206.35.99]) by mx1.freebsd.org (Postfix) with ESMTP id AB3008FC17 for ; Fri, 1 Jun 2012 15:08:08 +0000 (UTC) Received: from wojtek.tensor.gdynia.pl (localhost [127.0.0.1]) by wojtek.tensor.gdynia.pl (8.14.5/8.14.5) with ESMTP id q51F84Xk003676; Fri, 1 Jun 2012 17:08:04 +0200 (CEST) (envelope-from wojtek@wojtek.tensor.gdynia.pl) Received: from localhost (wojtek@localhost) by wojtek.tensor.gdynia.pl (8.14.5/8.14.5/Submit) with ESMTP id q51F84Kr003672; Fri, 1 Jun 2012 17:08:04 +0200 (CEST) (envelope-from wojtek@wojtek.tensor.gdynia.pl) Date: Fri, 1 Jun 2012 17:08:04 +0200 (CEST) From: Wojciech Puchar To: Polytropon In-Reply-To: <20120601163520.f130cdcd.freebsd@edvax.de> Message-ID: References: <20120601163520.f130cdcd.freebsd@edvax.de> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.2.7 (wojtek.tensor.gdynia.pl [127.0.0.1]); Fri, 01 Jun 2012 17:08:05 +0200 (CEST) Cc: Kaya Saman , 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 15:08:09 -0000 > and unbelievable narrow cases, when you don't have or can't > access a backup (which you should have even when using ZFS), > and you _need_ to do some forensic analysis on disks, ZFS > seems to be a worse solution than UFS. On ZFS, you never > can predict where the data will go. Add several disks to true. in UFS for example inodes are at known place, and flat structure instead of "tree" is used. even if some sectors are overwritten with garbage then fsck can scan over inodes and recover all that can be recovered. 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.