From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Sun, 01 Jun 2008 03:45:38 -0700 (PDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.168.29]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m51AjZCe018056 for ; Sun, 1 Jun 2008 03:45:35 -0700 Received: from proxy2.bredband.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id BB83E1D8903 for ; Sun, 1 Jun 2008 03:46:27 -0700 (PDT) Received: from proxy2.bredband.net (proxy2.bredband.net [195.54.101.72]) by cuda.sgi.com with ESMTP id jchEmKpSFwASjCja for ; Sun, 01 Jun 2008 03:46:27 -0700 (PDT) Received: from ironport2.bredband.com (195.54.101.122) by proxy2.bredband.net (7.3.127) id 4811833300B18985 for xfs@oss.sgi.com; Sun, 1 Jun 2008 12:46:26 +0200 Message-ID: <48427DEE.40400@stesmi.com> Date: Sun, 01 Jun 2008 12:46:06 +0200 From: Stefan Smietanowski MIME-Version: 1.0 Subject: Re: XFS: SB validate failed References: <3607657a0805291005k457791cej1c5f867da0f95965@mail.gmail.com> <483EE5BD.8020407@sandeen.net> <3607657a0805291255i59fd006fi9d6836cf528d19a6@mail.gmail.com> <483F0BC3.2050901@sandeen.net> <3607657a0805291400h3c50165lea6fbea919deed0f@mail.gmail.com> <483F1AED.3010808@sandeen.net> <3607657a0805291446t79808c63l664780c1cbc3d871@mail.gmail.com> <483F907A.3020108@sgi.com> <3607657a0805301019h4a49dc86ne8f1f019629a1c41@mail.gmail.com> <4840406F.50402@stesmi.com> <48408D3E.3090401@gmail.com> <48409981.1050405@stesmi.com> <48425148.1080105@gmail.com> In-Reply-To: <48425148.1080105@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Hamid Cc: Timothy Shimmin , Eric Sandeen , xfs@oss.sgi.com Hamid wrote: > >> I think you have the terminology a little mixed up. >> >> If you mount a something without supplying -o loop "mount" will assume >> the filesystem resides in a DEVICE. >> >> If you mount a something WHILE supplying -o loop you tell "mount" that >> it should mount it using a loop device. Note device here, it's trickery >> really as what it does is that "mount" will FIRST create a new device >> node "/dev/loop0" for example and then it will mount from that device >> node. >> > Thanks Stefan, Now it makes real sense. > > I guess I am back to my original question: > What does 'SB validate failed' indicate and what it really means to my > case ? > > fdisk reports the structure of the Jaz disk as: > > $ sudo fdisk -ul jaz7.img > > Disk jaz7.img (SGI disk label): 255 heads, 63 sectors, 0 cylinders > Units = sectors of 1 * 512 bytes > > ----- partitions ----- > Pt# Device Info Start End Sectors Id System > 8: jaz7.img1 3072 2091007 2087936 a SGI xfs > 9: jaz7.img2 0 3071 3072 0 SGI volhdr > 11: jaz7.img3 0 2091007 2091008 6 SGI volume > ----- Bootinfo ----- > Bootfile: /unix > ----- Directory Entries ----- > 0: sgilabel sector 3 size 512 > > I went ahead and tried to mount Partition 8 from image using the offset > and loop options of the mount command: > > $ sudo mount -t xfs -o loop,offset=$((512*3072)) jaz7-partition.img /mnt > mount: wrong fs type, bad option, bad superblock on /dev/loop1, > missing codepage or helper program, or other error > In some cases useful info is found in syslog - try > dmesg | tail or so > > And system log says: > > XFS: bad magic number > XFS: SB validate failed > > So I am guessing I have one of these 3 cases: > 1- Bad partition table, good file system > 2- Good partition table, corrupt file system > 3- Or both gone south!!! > > I checked the man pages of 'vh' on Irix. It seems that the volhdr > partition is 'usually' 2 megabytes but the disk in question has 3072*512 > bytes ? > Can this be a sign of corruption ? > > So where would you start looking at if you wanted to fix this problem ? > Partition table or the file system ? Personally I would hexdump the beginning of the disk looking for the xfs magic of the partition and then try to use that offset in mount. One way is : od -t c jaz7.img | grep X | head Look for X F S B, may be split on two lines for you. This is what my disk looks like but of course, it's on a DOS partition: 0077000 X F S B \0 \0 020 \0 \0 \0 \0 \0 \0 \0 ` \0 Then you have the offset (OCTAL!!) on the left, convert it to decimal, feed that to mount and see if it mounts. Also check if it's the same offset as the partition table is telling you or not. // Stefan