系统版本为rhel6.4，用8个3T的硬盘做了raid5之后，可用空间21T，划分500多G空间给系统用，之后的空间想给数据目录，发现无论是新建2T还是20T，都是只有672G，无论是新建pv还是直接格式化ext4，情况也是一样，实在是找不到怎么回事？求邦助，谢谢。
[root@localhost ~]# parted /dev/sda print
Model: DELL PERC H710 (scsi)
Disk /dev/sda: 21.0TB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End Size File system Name Flags
1 1049kB 211MB 210MB ext4 boot
2 211MB 33.8GB 33.6GB linux-swap(v1)
3 33.8GB 558GB 524GB lvm
4 558GB 21.0TB 20.4TB
[root@localhost ~]# partx /dev/sda
# 1: 2048- 411647 ( 409600 sectors, 209 MB)
# 2: 411648- 65947647 ( 65536000 sectors, 33554 MB)
# 3: 65947648-1089947647 (1024000000 sectors, 524288 MB)
# 4: 1089947648--1933576193 (1271443456 sectors, 650979 MB)
[root@localhost ~]# pvcreate /dev/sda4
Physical volume "/dev/sda4" successfully created
[root@localhost ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda3 rootvg lvm2 a-- 488.28g 166.28g
/dev/sda4 lvm2 a-- 672.32g 672.32g
