For context, see my answer:Move a logical volume from one volume group to another.I tried to use this recipe for real. See the transcript athttps://gist.github.com/anonymous/1611380eafd0c738ef0f8ad09e0f0ab0It looks like I didn't test this enough. While trying to apply this to my system, I got the following errorroot@orwell:/tmp# lvconvert --type raid1 --mirrors 1 /dev/newdebian/debian_boot /dev/md2  Logical volume newdebian/debian_boot successfully converted.root@orwell:/tmp# lvconvert --splitmirrors 1 --name debian_boot_copy /dev/newdebian/debian_boot  Unable to determine sync status of newdebian/debian_boot.  Unable to split newdebian/debian_boot while it is not in-sync.I'm not finding any information about this on the net, but I also think it's unlikely that I'm the first person in the world to run into this. Note that the two volume groups in this case are on separate md RAID devices. Here is what the layout currently looks like.And I merged the debian VG into the newdebian VG.This is an awkward position to be in - I may not be able to use my regular installation, which is on the debian VG, till this is fixed.root@orwell:/tmp# lvs -a -o name,copy_percent,devices newdebian  LV                     Cpy%Sync Devices                                          acl                             /dev/md1(80472)                                  boot                            /dev/md2(35761)                                  data                            /dev/md1(95835)                                  debian_boot                     debian_boot_rimage_0(0),debian_boot_rimage_1(0)  [debian_boot_rimage_0]          /dev/md1(0)                                      [debian_boot_rimage_1]          /dev/md2(36000)                                  [debian_boot_rmeta_0]           /dev/md1(117666)                                 [debian_boot_rmeta_1]           /dev/md2(35999)                                  debian_home                     /dev/md1(12158)                                  debian_root                     /dev/md1(238)                                    home                            /dev/md2(11920)                                  postgres                        /dev/md1(105563)                                 root                            /dev/md2(0)                                      swap                            /dev/md1(35999)                                  swap                            /dev/md1(113243)                                 vboxshare                       /dev/md1(117410)                                 video                           /dev/md1(42072)                                  video                           /dev/md1(83035)                                  windows                         /dev/md1(36952)                                  windows                         /dev/md1(80475)                                  windows                         /dev/md1(114338)                                 windows10                       /dev/md1(100955)                                 windows10                       /dev/md1(115618)  For the moment, I've converted back to linear root@orwell:/tmp# lvconvert --type linear /dev/newdebian/debian_boot  Unable to determine sync status of newdebian/debian_boot.  Logical volume newdebian/debian_boot successfully converted.but of course, I'd like to know what the problem is.
Unable to determine sync status errror when trying split LVM2 RAID 1 mirror
lvm