IMHO the striping, etc. is not very important because that is all inside the LV. What is important is finding a sector/block/whatever which looks like if it contains a PV administration. The same as you describe scanning to see if there is something that looks like the beginning of an ext (or other) fs. It is all the same, the first block of a partitions has the first bit of information that makes the contents of a partition (or a whole unpartitioned disk for that matter) a swap, or ext2/3/4 or Reiserfs, or …, or PV. But it will allways be a bit of a guess. After all it could just be a block of a JPEG file that looks like the beginning of an ext4 fs :(.
On 08/23/2012 02:18 PM, Carlos E. R. wrote:
> There was a post here by a poster that has been banned, and the post deleted, with a link to a
> software that claimed to be able to partially repair LVM.
it was a spam post…linking to an invitation to buy a product (live CD
i guess) ranging from about $70 to $600
the net is full of such offers…most offer open source software on a
live booting Linux…
–
dd
On 2012-08-23 16:11, dd@home.dk wrote:
> On 08/23/2012 02:18 PM, Carlos E. R. wrote:
>> There was a post here by a poster that has been banned, and the post deleted, with a link to a
>> software that claimed to be able to partially repair LVM.
>
> it was a spam post…linking to an invitation to buy a product (live CD i guess) ranging from
> about $70 to $600
Yes, I saw it.
The link itself was lost on nntp, curiously enough. Another gateway
> the net is full of such offers…most offer open source software on a live booting Linux…
I have no idea what it contains. About a month ago or so I tried photorec and testdisk to
rescue a damaged ntfs hard disk of a friend. It did not do a good enough job. The web page of
that opensource project did in fact recommend another product, this time payware. I tried it,
and it did a better job - but if you wanted the recovery to write files bigger than a megabyte
you had to pay. And I did pay (actually, my friend did). The payment method was clever enough
that you can pay after the detection process has run, which was nice because it took about four
hours to get there.
So I keep an open mind when it comes to recover data with closed source software - sometimes
your data is valuable enough to bite the bullet and pay. But it was cheaper than the spam we
got this time.
More recently I had to attempt a recovery of thousands of deleted files on my own system, and
again the tool, opensource this time, did not do a good enough job - possibly as much as it was
feasible. I’m not aware if there is a better closed source software to do it, but I might have
tried.
So you will understand that, even if it is spam, I would like to know how good is that software.
Backup, did you say? Mmmm. Maybe next time. 
–
Cheers / Saludos,
Carlos E. R.
(from 12.1 x86_64 “Asparagus” at Telcontar)
On 08/23/2012 04:38 PM, Carlos E. R. wrote:
> So you will understand that, even if it is spam, I would like to know how good is that software.
understand…but, the forums T&C don’t allow advertising without prior
approval, no matter how good the commercial product…
maybe that maker will become a sponsor…we could use some more of those
–
dd
I did try ‘reactivating’ the lvm group as robin_listas suggested (my websearching found a lot of articles outlining the same process) but I failed, I wasn’t confident tbh due to lacking some crucial information
hcvv you asked about the linux on /dev/sdb it was likely a live usb as I had used both partedmagic and OS 12.1 live usbs to look at/try things, as well plugging the drive into another linux machine, the availability of a bootable linux wouldn’t have been a problem as I have plenty of those
Cheers for the tips/info on backups from a couple of you guys, much appreciated, but ordinarily I have them, usually I have tar’d backups somewhere on the machine and rsync’d backups on another machine. Unfortunately the tars were inside the lvm group and the rsync backups were temporarily non-existent for reasons I didn’t go into to avoid the risk of boring people with a convoluted scenario that had no real bearing on the subject because if I had them the whole thread would’ve been irrelevant
Thanks for trying to help guys, I decided to cut my losses and just set everything up from scratch again, just have to deal with obsolete settings in some of the confs I did still have now because of version upgrades