From owner-freebsd-questions Fri Jun 8 2:44:39 2001 Delivered-To: freebsd-questions@freebsd.org Received: from guru.mired.org (okc-65-26-235-186.mmcable.com [65.26.235.186]) by hub.freebsd.org (Postfix) with SMTP id 367A037B405 for ; Fri, 8 Jun 2001 02:44:36 -0700 (PDT) (envelope-from mwm@mired.org) Received: (qmail 73041 invoked by uid 100); 8 Jun 2001 09:44:35 -0000 From: Mike Meyer MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15136.40579.787768.23014@guru.mired.org> Date: Fri, 8 Jun 2001 04:44:35 -0500 To: David Leimbach Cc: questions@freebsd.org, Subject: Re: softupdates crash -> data recovery ? In-Reply-To: <113986786@toto.iv> X-Mailer: VM 6.90 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid X-face: "5Mnwy%?j>IIV\)A=):rjWL~NB2aH[}Yq8Z=u~vJ`"(,&SiLvbbz2W`;h9L,Yg`+vb1>RG% *h+%X^n0EZd>TM8_IB;a8F?(Fb"lw'IgCoyM.[Lg#r\ Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > On Thu, Jun 07, 2001 at 05:10:12PM -0700, Randy Primeaux wrote: > > How might I go about recovering data from a disk after softupdates > > crashed? > > > > > > Shortly after enabling softupdates on /usr, I had a system freeze > > (back in January), and upon boot the next day, found: > > > > /dev/ad4s1f: CANNOT READ: BLK 16 > > /dev/ad4s1f: NOT LABELED AS A BSD FILE SYSTEM (unused) > > > > > > /dev/ad4s1f is /usr including /usr/home > > Disk is an IBM DTLA 307030. Either your disk failed so badly that the superblock can't be read, or something fried the superblock really thoroughly. Try using the alternate superblock - fdsck -b 32 /dev/ad4s1f - and see if you can recover from it. If that works, you'll get a new superblock, and can mount and use the system. If the alternate superblock at 32 is fried, you'll need to use another one. The list of them was printed when you newfs'ed the file system. If you didn't save the list, finding further alternates could be interesting. If the hardware is the problem, writing out the new superblock will fail. You'll need to copy the partition with dd using "conv=noerror", then fsck the copy. If you get to many errors during the copy, it's time to restore from the backups. In either case, it's time to trash the disk. David Leimbach types: > Hmmm... this would seem to suggest contrary information as to the value > of a soft-updates file system... No, this shows that sufficient hardware failures will kill any file system. A journaling file system wouldn't have helped here; it really needs a mirror. http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message