[pve-devel] [PATCH] Increases the dd read/write speed when migrating LVM disks. This should bring LVM migration speed up to match that of rsyncing qcows.

[Dietmar Maurer]

> +		    run_command([["dd", "if=$src", "bs=64M"],["/usr/bin/ssh",
> "root\@${target_host}",
> +			      "dd", 'conv=sparse', "of=$dst", "bs=64M"]]);

IMHO a block size of 64MB is a bit too large. I guess you can see the same 
speed improvements with much smaller sizes - mabe 1M is large enough?