[linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Ken Bass]

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Okay, I finally got to do what Stuart D. Gathman suggested. And it worked,
sort of.

The problem: the first PV in my LV started to die, and trashed a big portion
of the beginning of the physical drive - including the partition table,
partition info, and ext4 file structure. All I wanted at that point was to
recover what was on the rest of the other PVs in the LV. But nothing could
interpret whatever data was left. e2fsck, et al, all said they could not
find a superblock, even when I tried ones on the other PVs.

Since that original drive was really dying (SMART was spurting out messages
about that), it was somewhat difficult to read anything off of it. But
Stuart did recommend "dd_rescue" to move whatever it could from the dying
drive to a new drive. Which I did. Turns out that most of the access
problems were at the beginning of the drive (why I don't know). So I
basically copied in reverse, starting at the end of the drive. I did this
mainly hoping to find a valid superblock that I could use to bring back up
the LV and run e2fsck on it.

Long story short: dd_rescue did just that. I found a superblock, and ran
e2fsck to fix all of the problems.

NOW: I am left with a clean ext filesystem, but with about 300GB in
lost+found, and not other files. Just guessing on that amount, since that is
how much was on the LV before the crash. So the next logical and obvious
(and desperate) question is: how to I restore all (or any) of the files
under lost+found?

Most of them (that I am interested in)were either image files (jpg, png,
bmp), ISO images (DVD, CD), music files (mp3, flac, etc), and a few MS
executables. Is there a utiliity that can help restore these files, maybe
scan the lost+found files for these types?

Thanks to all for their help. I hope none of you ever have to go through
this yourself :-).

ken

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Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Brian McCullough]

On Wed, Jul 21, 2010 at 11:34:45AM -0700, Ken Bass wrote:
> Okay, I finally got to do what Stuart D. Gathman suggested. And it worked,
> sort of.
> 
> NOW: I am left with a clean ext filesystem, but with about 300GB in
> lost+found, and not other files. Just guessing on that amount, since that is
> how much was on the LV before the crash. So the next logical and obvious
> (and desperate) question is: how to I restore all (or any) of the files
> under lost+found?
> 
> Most of them (that I am interested in)were either image files (jpg, png,
> bmp), ISO images (DVD, CD), music files (mp3, flac, etc), and a few MS
> executables. Is there a utiliity that can help restore these files, maybe
> scan the lost+found files for these types?

Not a lot of help, probably, but the "file" command should at least give you some idea of what type of files they are.


Brian

Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Ken Bass]

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On Wed, Jul 21, 2010 at 11:54 AM, Brian McCullough <bdmc@bdmcc-us.com>wrote:

> On Wed, Jul 21, 2010 at 11:34:45AM -0700, Ken Bass wrote:
>

> Most of them (that I am interested in)were either image files (jpg, png,
> > bmp), ISO images (DVD, CD), music files (mp3, flac, etc), and a few MS
> > executables. Is there a utiliity that can help restore these files, maybe
> > scan the lost+found files for these types?
>
> Not a lot of help, probably, but the "file" command should at least give
> you some idea of what type of files they are.
>
>
Actually seems to be more help than I thought possible. I ran it
(recursively) through all of the files in the lost+found and the output sent
to a file. Looking through it, I first found several ISO files, and since
they all had labels as part of the structure, I could just move and rename
them.

Next I found a whole lot of audio type files, tagged with ID3. But that was
all of the information "file" could give. Is there a utility to read ID3
tags and generate a file name from it? I seem to remember I had many GBs of
mp3's, flac's, ape's, etc.,  and that would be a real tedious pain to try to
recognize and rename all of them :-(.

The same goes for MS applications (.exe). "file" did recognize them as such,
but, like the audio files, it didn't give enough information to tell what
they were.

So at least this debacle was not a complete unrecoverable catastrophe :-).
Thanks to everyone who helped.

FWIW: I got some helpful information from this page at Novell's site:
http://www.novell.com/coolsolutions/appnote/19386.html . But if you look at
the last step, it does say that if the first PV is trashed, you will be in
the same position as I was. Maybe someone should put together a wiki page
with that and the procedure I just went through? Just a wishful thought.

Thanks again,

ken

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Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Stuart D. Gathman]

On Thu, 22 Jul 2010, Ken Bass wrote:

> Next I found a whole lot of audio type files, tagged with ID3. But that was
> all of the information "file" could give. Is there a utility to read ID3
> tags and generate a file name from it? I seem to remember I had many GBs of
> mp3's, flac's, ape's, etc.,  and that would be a real tedious pain to try to
> recognize and rename all of them :-(.

The id3lib package provides id3info, which displays id3 tags.  There
are probably more modern packages, but that is what I use.  You can
automate naming the MP3 files using that in a script.

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Ken Bass]

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On Thu, Jul 22, 2010 at 7:02 PM, Stuart D. Gathman <stuart@bmsi.com> wrote:

> On Thu, 22 Jul 2010, Ken Bass wrote:
>
>  The id3lib package provides id3info, which displays id3 tags.  There
> are probably more modern packages, but that is what I use.  You can
> automate naming the MP3 files using that in a script.
>
>
That's what I was thinking of. if "id3info" can give me the artist, album,
disc#, track# and track name, then that's the first half. After that, I just
have to remember how to use all of those esotericially named shell utils to
rename each file (it has been quite a while for me :-(  ).

Again, thank you SO much. There were a few files that I really wanted/needed
to recover. Plus, I also needed the storage space back on the LAN server.

ken

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Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Stuart D. Gathman]

On Thu, 22 Jul 2010, Ken Bass wrote:

> Again, thank you SO much. There were a few files that I really wanted/needed
> to recover. Plus, I also needed the storage space back on the LAN server.

I always use mirrored disks with the md driver.  Simpler to use 
than Raid-5, flexible (remove a disk and take it else where for an instant
clone), performance boost for reads (but not writes), disks are
cheap, protects against simple disk failure - i.e. what you just suffered,
2 disk minimum requirement (vs. 3 or more for other RAID schemes).

Just add the md* devices as PVs to your volume group.

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.

Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[daytooner]

Thx. That's one try. 

BTW: what is a .milk file? There were several of these I found under several layers under lost+found.

Ken
-----Original Message-----

From:  Brian McCullough <bdmc@bdmcc-us.com>
Subj:  Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem
Date:  Wed Jul 21, 2010 11:58 am
Size:  1K
To:  LVM general discussion and development <linux-lvm@redhat.com>

On Wed, Jul 21, 2010 at 11:34:45AM -0700, Ken Bass wrote:
> Okay, I finally got to do what Stuart D. Gathman suggested. And it worked,
> sort of.
> 
> NOW: I am left with a clean ext filesystem, but with about 300GB in
> lost+found, and not other files. Just guessing on that amount, since that is
> how much was on the LV before the crash. So the next logical and obvious
> (and desperate) question is: how to I restore all (or any) of the files
> under lost+found?
> 
> Most of them (that I am interested in)were either image files (jpg, png,
> bmp), ISO images (DVD, CD), music files (mp3, flac, etc), and a few MS
> executables. Is there a utiliity that can help restore these files, maybe
> scan the lost+found files for these types?

Not a lot of help, probably, but the "file" command should at least give you some idea of what type of files they are.


Brian

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Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Brian McCullough]

On Wed, Jul 21, 2010 at 01:41:00PM -0700, daytooner@gmail.com wrote:
> Thx. That's one try. 
> 
> BTW: what is a .milk file? There were several of these I found under several layers under lost+found.

http://filext.com/file-extension/MILK

http://www.file-extensions.org/milk-file-extension

http://www.fileinfo.com/extension/milk



Brian

Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Ken Bass]

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On Wed, Jul 21, 2010 at 2:34 PM, Brian McCullough <bdmc@bdmcc-us.com> wrote:

> On Wed, Jul 21, 2010 at 01:41:00PM -0700, daytooner@gmail.com wrote:
> > Thx. That's one try.
> >
> > BTW: what is a .milk file? There were several of these I found under
> several layers under lost+found.
>
> http://filext.com/file-extension/MILK
>
> http://www.file-extensions.org/milk-file-extension
>
> http://www.fileinfo.com/extension/milk
>
>
MilkDrops? I didn't even have WinAmp installed. Maybe it, or some of its
plugins were installed by other a/v apps. I am guessing that I can ignore
them. But the funny thing is: these were the only files with any given
extension under lost+found after I fixed my LV filesystem.

ken

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Re: [linux-lvm] [SOLVED?] rebuilding LV ext4 filesystem

[Stuart D. Gathman]

On Thu, 22 Jul 2010, Ken Bass wrote:

> MilkDrops? I didn't even have WinAmp installed. Maybe it, or some of its
> plugins were installed by other a/v apps. I am guessing that I can ignore
> them. But the funny thing is: these were the only files with any given
> extension under lost+found after I fixed my LV filesystem.

I suspect it has to do with information about partially recovered files
or directories.  I wouldn't throw them out just yet.  Perhaps
a google on e2fsck and .milk ?

-- 
	      Stuart D. Gathman <stuart@bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
a Microsoft sponsored "Where do you want to go from here?" commercial.