Create GPT partition table

Sorry but you HAVE to go with rescue disk.

parted /dev/sdb
(parted) mklabel gpt
(parted) mkpart primary 0GB 100%
(parted) print
(parted) q

parted /dev/sda
(parted) mklabel gpt
(parted) mkpart primary 0GB 100%
(parted) print
(parted) q

Configure LVM

root@rescue ~ # pvcreate /dev/sda1
  Writing physical volume data to disk "/dev/sda1"
  Physical volume "/dev/sda1" successfully created
root@rescue ~ # pvcreate /dev/sdb1
  Writing physical volume data to disk "/dev/sdb1"
  Physical volume "/dev/sdb1" successfully created
root@rescue ~ # pvs
  PV         VG   Fmt  Attr PSize PFree
  /dev/sda1       lvm2 a--  2.73t 2.73t
  /dev/sdb1       lvm2 a--  2.73t 2.73t
root@rescue ~ # vgcreate storage /dev/sda1 /dev/sdb1
  Volume group "storage" successfully created
root@rescue ~ # vgs
  VG      #PV #LV #SN Attr   VSize VFree
  storage   2   0   0 wz--n- 5.46t 5.46t