[linux-lvm] Recovery of data in LVM from a corrupt disk

[Michael Loftis]

--On December 20, 2005 2:03:01 PM -0800 mymail mymail 
<internetbizmail at yahoo.com> wrote:

>
> I have a FC3 system with two disks. The first (/dev/hda) is a new disk on
> which I have a rebuilt system which has a new LVM installed. The other
> disk (/dev/hdc) is the system disk that failed. As I couldn't get hdc to
> boot, my intention is to access hdc by mounting it on the hda system to
> copy data around, or try other ways to recover what's on there. However
> whenever I try
>
>    # mount /dev/hdc2 /mnt
>    FAT: invalid media value (0x8e)
>    mount: you must specify the filesystem type
>
> I get filesystem not found errors. The filesystem type according to fdisk
> is 8e (LVM), but can I get at the data that's on there and then copy that?
>
> Any hints on how to recover this would be appreciated. I can find loads
> of info on LVM a! nd how it works, which is great when you have a working
> system, but not so good when it's corrupt!
>
> Any help on how to do backups and the best procedure to follow in the
> event of another disaster will also be useful -- there is nothing in the
> FAQs, etc I've seen on this.

LVM is not a filesystem, it's a block device layer.  If you're 
running/using LVM on the existing system it's vgscan and vgchange on 
startup should have activated all the old LVs/VGs and mapped them to 
/dev/VGNAME/LVNAME -- those are the devices you mount.