[SOLVED] LVM2 management - Clarity Needed

Hi
Hopefully someone can clear my befuddled and foggy grey matter:

Running Ubuntu server 64bit 18.04 LTS with an LVM array on an HP Proliant NAS:

sudo lvdisplay
--- Logical volume ---
LV Path /dev/vgpool/logical_vol1
LV Name logical_vol1
VG Name vgpool
LV UUID BOWg21-9MFT-Mq1z-xheE-nHiE-G7ip-Mw7FrP
LV Write Access read/write
LV Creation host, time proliant, 2019-09-09 12:52:11 +0930
LV Status available
# open 1
LV Size 10.46 TiB
Current LE 2742352
Segments 4
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

PV VG Fmt Attr PSize PFree
/dev/sdb1 vgpool lvm2 a-- 1.36t 0
/dev/sdc1 vgpool lvm2 a-- <1.82t 0
/dev/sdd1 vgpool lvm2 a-- <3.64t 0
/dev/sde1 vgpool lvm2 a-- <3.64t 0

PFree is being reported as zero. However, I know that at most there is only about 5T stored on the LVM array.

How can I check that all available HDD space has been allocated to the array?

NB: IIRC when I set it up a year or two ago I allocated 100%FREE for every device.

Thanks