From owner-freebsd-current@FreeBSD.ORG Thu May 24 21:02:50 2012 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id AB8271065672; Thu, 24 May 2012 21:02:50 +0000 (UTC) (envelope-from peter@rulingia.com) Received: from vps.rulingia.com (host-122-100-2-194.octopus.com.au [122.100.2.194]) by mx1.freebsd.org (Postfix) with ESMTP id 1A4478FC20; Thu, 24 May 2012 21:02:49 +0000 (UTC) Received: from aspire.rulingia.com (12.58.233.220.static.exetel.com.au [220.233.58.12]) by vps.rulingia.com (8.14.5/8.14.5) with ESMTP id q4OL2cnS070426 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 25 May 2012 07:02:43 +1000 (EST) (envelope-from peter@rulingia.com) Received: from aspire.rulingia.com (localhost [127.0.0.1]) by aspire.rulingia.com (8.14.5/8.14.5) with ESMTP id q4OL1Um9025650 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Fri, 25 May 2012 07:01:30 +1000 (EST) (envelope-from peter@aspire.rulingia.com) Received: (from peter@localhost) by aspire.rulingia.com (8.14.5/8.14.5/Submit) id q4OL1TEk025649; Fri, 25 May 2012 07:01:29 +1000 (EST) (envelope-from peter) Date: Fri, 25 May 2012 07:01:28 +1000 From: Peter Jeremy To: Lev Serebryakov Message-ID: <20120524210128.GC2675@aspire.rulingia.com> References: <38A5BC8F-A8FB-4371-AB1D-9548F5957254@lists.zabbadoz.net> <20120523131046.GC2358@deviant.kiev.zoral.com.ua> <12410676034.20120524013853@serebryakov.spb.ru> <8D72700F5CA4461BAD1C98908689CB9E@multiplay.co.uk> <1239922227.20120524120421@serebryakov.spb.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="QRj9sO5tAVLaXnSD" Content-Disposition: inline In-Reply-To: <1239922227.20120524120421@serebryakov.spb.ru> X-PGP-Key: http://members.optusnet.com.au/peterjeremy/pubkey.asc User-Agent: Mutt/1.5.21 (2010-09-15) Cc: freebsd-current FreeBSD Subject: Re: UFS+J panics on HEAD X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 May 2012 21:02:50 -0000 --QRj9sO5tAVLaXnSD Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2012-May-24 12:04:21 +0400, Lev Serebryakov wrote: > I afraid, that after real hardware failure (like real HDD death, >not these pseudo-broken-hardware situations, when HDDs is perfectly >alive and in good condition), all data will be lost. I could restore >data from remains of FFS by hands (format is straightforward and >well-known), but ZFS is different story... If your disk dies then you need a redundant copy of your data - either via backups or via RAID. Normally, you'd run ZFS with some level of redundancy so that disk failures did not result in data loss. That said, ZFS is touchier about data - if it can't verify the checksums in your data, it will refuse to give it to you - whereas UFS will hand you back a pile of bytes that may or may the same as what you gave it to store. And you can't necessarily get _any_ data off a failed disk. > Yes, backups is solution, but I don't have money to buy (reliable) >hardware to backup 4Tb of data :( 4TB disks are available but not really economical at present. 2TB disks still seem to be the happy medium. If your data will compress down to 2TB then save it to a disk, otherwise split your backups across a pair of disks. A 2TB disk with enclosure is < I attended "Solaris internals" 5-days training four years ago (when I >worked for Sun Microsystems), and instructor says same words... I have had lots of problems at $work with Solaris UFS quietly corrupting data following crashes. At least with ZFS, you have a detter chance of knowing when your data has been corrupted. --=20 Peter Jeremy --QRj9sO5tAVLaXnSD Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (FreeBSD) iEYEARECAAYFAk++oagACgkQ/opHv/APuIfq2wCfZkmGVcZ3OyuGR9PoJBAS2t0U jFkAnRK4dgIIeIouTRmjvIliJm8+jKPV =a6g6 -----END PGP SIGNATURE----- --QRj9sO5tAVLaXnSD--