Date: Wed, 20 Jul 2011 10:54:56 +0200 From: "DA Forsyth" <d.forsyth@ru.ac.za> To: freebsd-fs@freebsd.org, freebsd-questions@freebsd.org Subject: Re: How to fix bad superblock on UFS2? Message-ID: <4E2697E0.27289.3E5BF8BB@d.forsyth.ru.ac.za> In-Reply-To: <alpine.BSF.2.00.1107201037320.25966@mp2.macomnet.net> References: <4E257889.12343.39F99213@d.forsyth.ru.ac.za>, <alpine.BSF.2.00.1107201037320.25966@mp2.macomnet.net>
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On 20 Jul 2011 , Maxim Konovalov entreated about "Re: How to fix bad superblock on UFS2?": > Try to use tools/tools/find-sb to locate superblocks. Thankyou Maxim I may yet need to use that on another partition, but last night I achieved some success by hacking fsck_ffs to display what it is doing. By doing this I found that it considers the 'first alternate' superblock to be the one in the LAST cylinder group. So, by using dd to copy a working superblock to block 128 and to the last one listed by 'newfs -N', fsck_ffs could then actually recover some files. Since I probably broke more things on this partition than were broken by the 'disk smoke event', I was not surprised when only about half the drives files showed up in lost+found and the primary folder is now empty (the whole drive is a Samba share with quotas, so I create a folder to share so that users cannot mess with the quota.* files). Not a problem for this partition as I have a full level 0 dump. I now have 2 more partitions to resurrect.... both report 'Cannot find file system superblock' though 'newfs -N' shows a sensible list of them, so I have hope. But, further thanks to you for pointing out find-sb, because in googling for that I found various other very useful things, including http://www.chakraborty.ch/tag/raid-filesystem-partition-recovery-ufs- freebsd/ which at the least, points out things to avoid doing (-: thanks -- DA Fo rsyth Network Supervisor Principal Technical Officer -- Institute for Water Research http://www.ru.ac.za/institutes/iwr/
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