Hi, I reinstalled a second harddisk and tried to get it in my lvm-group VolGroup00. Before i struggled around somewhat :-( Now, i get the following errormessage, if i do vgdisplay Couldn't find device with uuid 'WyCdOD-T3fq-r7gc-pFon-e3C1-Ay8n-EdGyEE'. Couldn't find all physical volumes for volume group VolGroup00. Couldn't find device [root@frodo lvm]# lvmdiskscan /dev/sda1 [ 101,94 MB] /dev/sda2 [ 8,37 GB] LVM physical volume /dev/sdb1 [ 16,96 GB] LVM physical volume 0 disks 1 partition 0 LVM physical volume whole disks 2 LVM physical volumes How can i remove the device 'WyCdOD-T3fq-r7gc-pFon-e3C1-Ay8n-EdGyEE' out of this group? This should be /dev/sdb1, which i did wrong before. so now, if i want to vgextend VolGroup00 /dev/sdb1 i get this: Couldn't find device with uuid 'WyCdOD-T3fq-r7gc-pFon-e3C1-Ay8n-EdGyEE'. Couldn't find all physical volumes for volume group VolGroup00. Couldn't find device with uuid 'WyCdOD-T3fq-r7gc-pFon-e3C1-Ay8n-EdGyEE'. Couldn't find all physical volumes for volume group VolGroup00. Volume group "VolGroup00" not found Heeeeeeeeeeeeeeeeeeeelp please Roger