OK folks, I'm back at it again. Instead of taking my J4400 ( 24 x 1T disks) and making a big RAID60 out of it which Linux cannot make a filesystem on, I'm created 4 x RAID6 which each are 3.64T I then do : sfdisk /dev/sd{b,c,d,e} <<EOF ,,8e EOF to make a big LVM partition on each one. But then when I do : pvcreate /dev/sd{b,c,d,e}1 and then pvdisplay It shows each one as only half its actual size. But if I take the last one and wipe the partition table and just do pvcreate on the entire disk, it works pvcreate /dev/sde And then if I take the results from that and use the size to force a size on another PV I get it right too pvcreate /dev/sdd1 --setphysicalvolumesize=3.64T I'd use the entire disk expect that this seems dangerous to me because you do "sfdisk -l" and the disk appears to have no partition table which might entice someone to thing it is unused. And I'm not sure whether it is safe to use setphysicalvolumesize. Anyone know for sure? What are my alternatives? "/dev/sdb1" is a new physical volume of "1.64 TB" --- NEW Physical volume --- PV Name /dev/sdb1 VG Name PV Size 1.64 TB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID 7bzxpQ-Md1o-Z73g-YzLX-xxj7-nszh-LucEFW "/dev/sdc1" is a new physical volume of "1.64 TB" --- NEW Physical volume --- PV Name /dev/sdc1 VG Name PV Size 1.64 TB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID tlpJ6A-LPs1-NFbl-h1AZ-5aBX-yOuO-phcwWD "/dev/sdd1" is a new physical volume of "3.64 TB" --- NEW Physical volume --- PV Name /dev/sdd1 VG Name PV Size 3.64 TB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID ifwmQQ-AOvK-Ke6L-2gEy-aJgJ-bb8d-DaJJDD "/dev/sde" is a new physical volume of "3.64 TB" --- NEW Physical volume --- PV Name /dev/sde VG Name PV Size 3.64 TB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID VPptAS-CFul-Awe9-TI7E-W9jq-zVdx-1mJjDR [root at solexa1 ~]# -- “Don't eat anything you've ever seen advertised on TV” - Michael Pollan, author of "In Defense of Food"