Matthew Steven - Virtualization

Copying a Virtual Machine lv or Partition Over SSH

Matt — Sat, 20 Feb 2010 17:26:36 +0000

Copying a Logical Volume or Partition over SSH

This should only be attempted on either a snapshot lvm volume, or an unmounted hard drive partition!

Using ssh and dd you can copy any LVM or (unmounted) hard drive partition over the internet to a new machine easily. You can do a "push" or "pull" copy. Here's a "push" copy:

dd if=/dev/vg0/partition-snapshot bs=1k |
ssh remotehost dd of=/dev/vg0/partition-destination bs=1k

Creating a LVM Mirror with LVM2's lvconvert tool.

Matt — Sun, 10 May 2009 22:00:11 +0000

Here’s one for the hall of fame of terrible error messages.
When trying to add a mirror to a LVM volume on a linux box, you get this message:
#lvconvert -m 1 disks/root /dev/sdb2

Not enough PVs with free space available for parallel allocation.
Consider --alloc anywhere if desperate.
This message is completely useless, we have TONS of free extents on both disks. So we check for help

Workaround for Crashing Xen Kernel on Ubuntu Hardy High Memory Systems

Matt — Sun, 10 May 2009 21:58:21 +0000