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Migrating Volume between Volume Groups (RHEL)

Issue:  I have 2 x 2 Disk Software RAID arrays in my host running a number of Virtual Machines.  Initially I had created all of the VMs on the same disks as the OS (2 x 500GB RAID 1) and I would like to spread them out.

This is not elegant, but in my initial investigation, I was unable to find a way to migrate Volumes.  I found numerous way to mirror devices, or to manipulate whole devices.

[root@llrh6kvm01 ~]# lvdisplay /dev/vg_llrh6kvm01/VM_LLRHEVM01
  --- Logical volume ---
  LV Path                /dev/vg_llrh6kvm01/VM_LLRHEVM01
  LV Name                VM_LLRHEVM01
  VG Name                vg_llrh6kvm01
  LV UUID                K8kpKm-H4WR-GwKS-EXM8-kJDx-FPFs-yrlOGW
  LV Write Access        read/write
  LV Creation host, time llrh6kvm01.ncell.lab, 2012-09-04 08:48:45 -0500
  LV Status              NOT available
  LV Size                36.00 GiB
  Current LE             9216
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto

[root@llrh6kvm01 ~]# lvcreate -L36G -nVM_LLRHEVM01 vg_STG
  Logical volume "VM_LLRHEVM01" created
[root@llrh6kvm01 ~]# dd if=/dev/vg_llrh6kvm01/VM_LLRHEVM01 of=/dev/vg_STG/VM_LLRHEVM01 

NOTE: since this is the my first/only Volume in the VG on the 2 other disks, I could have added the 2 disk metadevice (md127) and attached a mirror to my single volume, then detached the mirror and did a vgsplit of the 2 disk device (md127).  I'm not happy with this result at this time, but I have other stuff I need to get done and I will have to revisit this one someday soon.


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