vgsplit needs lvs on source vg to be inactive

Today I decided to unmirror part of my lvm2 disks. I started off with vg00 on top of md1 (raid1). I wanted end up with vg00 on top of md2 (raid1) and vg01 on top of sda3 and sdb3 (concatenation). I've come all the way to have vg00 on top off md2 and sdb3. The last step would be to split off sda3 into vg01 and add sda3 to it.

The error I am getting is:

# vgsplit -v vg00 vg01 /dev/sdb3
    Checking for volume group "vg00"
    Checking for volume group "vg01"
    Wiping cache of LVM-capable devices
  Logical volumes in "vg00" must be inactive

I did deactivate (lvchange) the lv that is using /dev/sdb3. But that doesn't seem enough. Does vgsplit actually need ALL lvs to be inactive? This makes little sense to me since the other lvs are not affected at all by vgsplit.

I've found
http://www.redhat.com/archives/fedora-list/2007-January/msg03485.html
which suggests that vgsplit can only be done with all lvs inactive. This would be mean booting from a cdrom for me as my root filesystem is on vg00. So far I have been doing all this online, and I'd like to keep it that way.

Is this at all possible? Can someone confirm that vgsplit needs all lvs on the source vg to be inactive?

Sincerely,

Richard van den Berg