SLES 10 SP4 system LV needs expansion.
VG still remaining capacity 120G, but these can not be assigned to a 900G capacity is in the LV.
When prompted expansion LV, LV maximum capacity of 1T.
How to solve this problem?

=================vg information===================
VG #PV #LV #SN Attr VSize VFree
datavg 15 9 0 wz--n- 1.46T 122.00G
=================vg detail information===================
--- Volume group ---
VG Name datavg
System ID
Format lvm2
Metadata Areas 15
Metadata Sequence No 30
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 9
Open LV 9
Max PV 0
Cur PV 15
Act PV 15
VG Size 1.46 TB
PE Size 4.00 MB
Total PE 384000
Alloc PE / Size 352768 / 1.35 TB
Free PE / Size 31232 / 122.00 GB
VG UUID ImxEpJ-y0c4-d2xs-2EAt-eQF0-UBaU-GF2W2P
=================lv information===================
LV VG Attr LSize Origin Snap% Move Log Copy%
ldatalv datavg -wi-ao 998.00G
--- Logical volume ---
LV Name /dev/datavg/ldatalv
VG Name datavg
LV UUID Fmok2p-YDaD-YqjU-b9ax-3XZM-N2eZ-x1THww
LV Write Access read/write
LV Status available
# open 2
LV Size 998.00 GB
Current LE 255488
Segments 12
Allocation inherit
Read ahead sectors 0
Block device 253:12