Hello all: I'm having a strange problem with GNBD and LVM on two fully updated CentOS 5.5 x86_64 systems. On node1, I have exported a gnbd volume. lvcreate -L 500M -n mirrortest_lv01 mirrorvg gnbd_serv gnbd_export -d /dev/mirrorvg/mirrortest_lv01 -e node1_lv01 On node2 I have imported the volume: gnbd_import -i node1 Next, on node2 I attempt to create a mirrored LV with the imported GNBD volume and a local disk: fdisk /dev/gnbd/node1_lv01 then create an LVM partition fdisk /dev/sdb then create an LVM partition I can then create a volume group with those two disks: pvs vgcreate mirrorvg /dev/sdb1 /dev/gnbd0 The problem occurs when I try to create a mirrored LV using the above VG. [root at vm-helios-002 ~]# lvcreate --mirrorlog core -L 256M -n mirroredlv01 -m 1 mirrortestvg Insufficient suitable allocatable extents for logical volume : 64 more required Unable to allocate extents for mirror(s). It doesn't matter what disk sizes are available. Even creating a non-mirrored LV causes issues: [root at vm-helios-002 ~]# lvcreate -L 256M -n mirroredlv01 mirrortestvg Error locking on node 192.168.8.152: device-mapper: create ioctl failed: Device or resource busy Error locking on node 192.168.8.151: Volume group for uuid not found: xCTR5M2kOEBiLM7eSRntez2y2VKy9vvqnSs6LTC99x9kIsAdNI2l8CH90h6BYKsH Aborting. Failed to activate new LV to wipe the start of it. [root at vm-helios-002 ~]# The other issue that's occurring is that even if I remove the GNBD PV from the mirrortestvg, it still gives the error (i.e., using just local disk). Not sure where to look at this point. I suspect it has something to do with the cluster locking, but the configuration is really basic and specifies no clustered volumes.