# LVM disaster - help!

## stdPikachu

So I tried adding a new hard drive to my LVM with the intention of moving the data onto the newer disc (sde) and putting the older disc (sdc) in a different computer, and I appear to have ended up with no data at all.

Original LVM was a JFS partition. Following the instructions here http://www.tldp.org/HOWTO/LVM-HOWTO/removeadisk.html I did the following:

pvcreate /dev/sde

vgextend lvmstor /dev/sde

pvmove /dev/sdc /dev/sde

vgreduce dev /dev/sdc

I then popped out sdc in the hope that the system woud pick up the changes.

Now there's no data at all available in /dev/mapper/lvmstor-storage, nor can I mount it:

```
prospero ~ # mount /dev/mapper/lvmstor-storage /mnt/temp/

mount: /dev/mapper/lvmstor-storage: can't read superblock
```

And a fsck doesn't seem to help either:

```
prospero ~ # fsck.jfs /dev/mapper/lvmstor-storage

fsck.jfs version 1.1.8, 03-May-2005

processing started: 2/10/2008 12.40.34

Using default parameter: -p

The current device is:  /dev/mapper/lvmstor-storage

ujfs_rw_diskblocks: Input/output error

ujfs_rw_diskblocks: Input/output error

Superblock is corrupt and cannot be repaired

since both primary and secondary copies are corrupt.

 CANNOT CONTINUE.
```

Can anyone point out where I went wrong? And does anyone know if it's fixable? I still have both of the old discs available but can't get either of them to mount on their own either.

```
prospero ~ # vgscan

  Reading all physical volumes.  This may take a while...

  /dev/dm-0: read failed after 0 of 4096 at 1000198832128: Input/output error

  /dev/dm-0: read failed after 0 of 4096 at 0: Input/output error

  Found volume group "lvmstor" using metadata type lvm2

prospero ~ # pvscan

  /dev/dm-0: read failed after 0 of 4096 at 1000198832128: Input/output error

  /dev/dm-0: read failed after 0 of 4096 at 0: Input/output error

  PV /dev/sdf1   VG lvmstor   lvm2 [931.51 GB / 0    free]

  PV /dev/sdc1                lvm2 [931.51 GB]

  Total: 2 [1.82 TB] / in use: 1 [931.51 GB] / in no VG: 1 [931.51 GB]
```

----------

## frostschutz

 *http://www.tldp.org/HOWTO/LVM-HOWTO/removeadisk.html wrote:*   

> Backup Your System
> 
> You should always backup your system before attempting a pvmove operation.

 

Did you follow that step too?

Also, why did you vgreduce dev /dev/sdc, shouldn't it be lvmstor in your case?

How was the old LVM volume and its partitions created? Did you change the size of anything later on? If not, then the data on the disks may not be fragmented, allowing easy data recovery, since pvmove does not actually delete anything from the old disk. It only forgets that it was ever there, so if you search the disc for your partition header you may actually still find it more or less intact. Of course if you did a live move while the partition was mounted, it may be corrupt if data was written on the disk in the meantime.

----------

