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Groups > comp.os.linux.setup > #2637
| From | Harry <simonsharry@gmail.com> |
|---|---|
| Newsgroups | comp.os.linux.setup |
| Subject | Re: No success repairing my ext4 file system so far, PLEASE HELP! |
| Date | 2012-04-14 20:13 -0700 |
| Organization | http://groups.google.com |
| Message-ID | <33504745.932.1334459589543.JavaMail.geo-discussion-forums@pbcsi9> (permalink) |
| References | (12 earlier) <jmagdl$i8t$1@omega-3a.local> <4c648a6a-b902-4210-830d-f72cce4b3054@j9g2000pbn.googlegroups.com> <jmbs9n$uee$1@omega-3a.local> <74aae4b7-8045-4a9a-8574-1d8f86e51fe9@gh10g2000pbc.googlegroups.com> <jmd6hs$8q5$1@omega-3a.local> |
On Sunday, April 15, 2012 6:29:40 AM UTC+5:30, Robert Nichols wrote:
> On 04/14/2012 08:35 AM, Harry wrote:
> >
> > $ mv /etc/lvm /etc/lvm.off
> >
> > $ pvscan
> > PV /dev/sdb2 lvm2 [74.04 GiB]
> > Total: 1 [74.04 GiB] / in use: 0 [0 ] / in no VG: 1 [74.04 GiB]
> ^^^^^^^^^^^^^^^^
> I'm having a hard time imagining what could have happened to make it
> appear that there was nothing in use inside that PV, especially since
> 'pvck' did find metadata records in there. Had this system been
> running for a long time without rebooting prior to your escapade?
> That would raise the possibility that the structures on disk had
> been damaged for quite a while, and the system couldn't have survived
> a reboot.
>
> Now, I'm wondering what your chances would be of reconstructing the
> VGs and LVs from the data in the backup files. If those volumes had
> ever been resized or rearranged since they were created, I fear your
> chances of success would be just about nil, but I don't know what
> else to suggest. I think I'd want to play around with that on newly
> created structures on another disk before trying it for real.
>
> --
> Bob Nichols AT comcast.net I am "RNichols42"
This is what, I believe, I did.
The 80G sdb that I'm trying to recover now, used to be sda in my system earlier. I then installed a 250G sdb in the system, installed Fedora 16 on it, made sdb bootable, and then booted my sytsem.
Now, my system was booting just fine from sdb. In my ignorance (of the low, system-level details of MBR, partitioning, BIOS, etc), I thought that if I copied the first 446 bytes of MBR of sdb (which is working fine right now for me) to sda, then I might be able to boot from sda also if I were to place sda into another system. Since these 446 bytes would be pure boot code which would be common to both sda and sdb (esp, since both had Fedora 16 installs on them) and with no data in it, I thought, I had nothing to lose in trying this operation out: at worst, sda would continue to remain non-bootable, at which point I'd look for some other solution.
So, I fearlessly issued a
dd if=/dev/sdb of=/dev/sda bs=446 count=1
and, I believe, sda continued to remain non-bootable.
Since, mentally, I tend to feel more comfortable with sda being the primary/bootable disk in my system, at this point I physically switched sda and sdb cables in my system.
I still didn't think anything was seriously wrong; I thought, I should be able to fix things now. Now, because I didn't understand LVM *at all* (I only have a very high-level idea, even now!), I incorrectly thought that the sdb2 partition (shown by fdisk -l) was really an ext4 filesystem (and 'not' an LVM volume!), and 'all' I had to do in order to be able to mount it was to use the standard methods suggested on the Net. (sdb was being reported as having a bad superblock and ext4 supposedly has redundant backups of this stored in it which one could use to repair it.) When I couldn't mount/repair, I posted the question here,
http://superuser.com/questions/410796/unable-to-repair-an-ext4-filesystem-with-bad-superblock .
---------------
Note: When this ext4 repair attempt didn't succeed on the sdb2 (partition), I even (incorrectly) tried the commands on sdb (the device) using various superblock offsets. Because the e2fsck man page has this statement in it
"The location of the backup superblock is dependent on the filesystem's blocksize.
For filesystems with 1k blocksizes, a backup superblock can be found at block 8193; for
filesystems with 2k blocksizes, at block 16384; and for 4k blocksizes, at block 32768."
, I even tried this command by assuming different blocksizes, for I thought I wouldn't be able to accurately and easily find out the actual blocksize of the filesystem given that it is in a 'broken' state at this point.
---------------
At this point, someone on this forum enlightened me that, because it was an LVM and not an ext4, ext4 repair tools were not working.
I *hope* these ext4 repair commands didn't mess up the LVM; each superblock offset I would specify would fail to get recognized as a valid superblock by e2fsck and so the repair operation would fail. Had the e2fsck command really succeeded by incorrectly identifying some random junk as a valid superblock, then I could understand (*now*) how it may have corrupted the LVM that I'm now struggling to bring back to life.
Only at this point and not any earlier, did I begin to anticipate serious trouble ahead and decided to clone /dev/sdb. Therefore, strictly speaking, the cloned sdb image I have now, does NOT reflect the state of things immediately after the 'MBR 446-byte overwrite' operation. I'm still hoping that none of my repair attempts (via e2fsck on both the device-sdb and the partition-sdb2!) corrupted the LVM on sdb2.
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No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 03:29 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 11:46 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 04:08 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 12:36 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 05:25 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 13:49 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 06:09 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 19:18 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 11:49 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-12 18:27 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-12 18:51 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 12:12 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2012-04-12 17:15 -0400
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 20:30 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 06:58 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 07:13 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-13 19:29 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 21:27 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-14 07:58 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-14 06:35 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-14 19:59 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-14 19:58 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-14 20:13 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-15 15:14 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 02:39 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-16 08:50 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 08:02 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 10:39 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 11:08 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-16 15:58 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 23:02 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Robert Nichols <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-17 10:58 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-18 21:53 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-19 16:45 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-19 18:34 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-20 17:19 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-21 20:37 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-25 16:01 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-28 16:32 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-16 19:15 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 21:20 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 21:40 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 21:56 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-16 18:47 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 20:19 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-13 15:22 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! J G Miller <miller@yoyo.ORG> - 2012-04-13 17:13 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 21:58 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 15:50 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! The Natural Philosopher <tnp@invalid.invalid> - 2012-04-12 21:37 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 15:46 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 09:35 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 18:57 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-12 15:59 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 16:39 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 09:53 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 19:03 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 09:48 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 19:07 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 18:43 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 10:55 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-12 18:07 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 19:20 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 19:11 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Richard Kettlewell <rjk@greenend.org.uk> - 2012-04-12 20:39 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-13 16:50 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-13 21:24 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Doug Freyburger <dfreybur@yahoo.com> - 2012-04-16 19:04 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-16 21:44 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-17 17:18 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-17 18:41 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 19:09 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 10:46 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 19:13 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-12 12:21 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! unruh <unruh@invalid.ca> - 2012-04-12 20:12 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! g.fink@gmx.net (Gernot Fink) - 2012-04-12 18:20 +0000
Re: No success repairing my ext4 file system so far, PLEASE HELP! The Natural Philosopher <tnp@invalid.invalid> - 2012-04-12 21:35 +0100
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-19 06:43 -0700
Re: No success repairing my ext4 file system so far, PLEASE HELP! Bob <SEE_SIGNATURE@localhost.localdomain.invalid> - 2012-04-19 11:29 -0500
Re: No success repairing my ext4 file system so far, PLEASE HELP! Harry <simonsharry@gmail.com> - 2012-04-19 18:50 -0700
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