recover LVM after hdd crash

Question

Yesterday, one hdd of my LVM crashed (smart-error)

The Machine has the following setup:
- 4 hdds
- 1 Partition Raid10 (System, 4*50GB)
- 1 Partition normal (/boot, 200MB, sda)
- 1 Partition LVM2 (Data, 4*~850GB)
- Ubuntu 10.04 Server (headless)

Now my lvm won't mount anymore, Ubuntu asks me to skip or manually recover on bootup. When I press S the system starts, but without my lvm getting mounted.

Now my system partition does not seam to be affected (/proc/mdstat looks as usual) an /boot works fine, too.

What I will try now is to
- buy a new hdd
- Integrate the hdd in my lvm
- Try to remove the sda-part of the lvm (copy it over to the new sde, or whatever lvm wants)
- Do the raid stuff (I think I'll find out how to do that, otherwise I'll ask a separate question)

Now my problems:
- How can I remove sda from the lvm (remove meaning copy contents and mark partition as not in use so I can unplug the drive)?
- If I am not able to remove the partition normally, are there any tools to recover the files on this partition, so I could manually copy them to the "new" lvm?

Thank you for your help

EDIT:
separated solution from Question

Answer 1

thinking pvmove is the command-line you are looking for...details here: http://tldp.org/HOWTO/LVM-HOWTO/removeadisk.html

Answer 2

It's not too clear to me whether your LVM is on top of RAID or not? If not then you're flat out of luck getting any data off of the LVM.

Answer 3

Computer works now. Here my detailed steps:
My sda (faulty drive) partitions looked like this:
sda1: /boot
sda2: raid10 member (system)
sda3: lvm member

• Attach new replacement hdd
• dd if=/dev/sda of=/dev/sde (copy the cotents of the faulty hdd to the new one, actually I did ctrl+c after a minute as I only needed the partition table)
• dd if=/dev/sda1 of=/dev/sde1 (copy /boot partition to the new disk)
• vgextend my_volume_group /dev/sde3 (add the lvm partition of the new disk to my lvm)
• pvmove /dev/sda3 (move the data of the faulty drive to another drive)
• Remove sda2 from my raid10
• changed fstab to get /boot from sda1 not by uuid (as this changes when replacing hdd)
• grub-install /dev/sde (as it's an upgraded version from 8.04, newer versions would need grub2-install)

now my sde partitions lokked the follow:
sde1: /boot
sde2: raid partition (not initialized)
sde3: lvm partition (initialized, lvm worked again)

I shutdown the computer, replaced the harddisk (so sde would be sda, removed old sda) and reboot
EVERYTHING worked! I did not even have to use a live cd to fix bootloader/other stuff, miraculously sda2 was recognised as raid10 member and was automatically initialized!