嗨各位先進好

小弟想要詢問個問題，這是個 hyperV VM，請問磁區經過 lvm 管理後，為什麼容量只用了 506.2 GB 左右？

資訊如下：
[root@XXXXXXX ~]# fdisk -l

Disk /dev/sda: 805.3 GB, 805306368000 bytes
255 heads, 63 sectors/track, 97906 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000b72d5

Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 16579 132656128 8e Linux LVM
/dev/sda3 16579 29633 104857920+ 83 Linux
/dev/sda4 29634 65270 286254202+ 83 Linux

Disk /dev/mapper/VolGroup-lv_root: 424.1 GB, 424128020480 bytes
255 heads, 63 sectors/track, 51563 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/VolGroup-lv_swap: 4261 MB, 4261412864 bytes
255 heads, 63 sectors/track, 518 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/VolGroup-lv_home: 77.9 GB, 77888225280 bytes
255 heads, 63 sectors/track, 9469 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 51

[root@XXXXX ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 VolGroup lvm2 a-- 126.51g 0
/dev/sda3 VolGroup lvm2 a-- 100.00g 0
/dev/sda4 VolGroup lvm2 a-- 272.99g 27.99g
[root@XXXXX ~]# lvs
LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert
lv_home VolGroup -wi-ao--- 72.54g
lv_root VolGroup -wi-ao--- 395.00g
lv_swap VolGroup -wi-ao--- 3.97g
[root@XXXXX ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup 3 3 0 wz--n- 499.50g 27.99g

補
[root@XXXXX ~]# parted -l
Model: Msft Virtual Disk (scsi)
Disk /dev/sda: 805GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 1049kB 525MB 524MB primary ext4 boot
2 525MB 136GB 136GB primary lvm
3 136GB 244GB 107GB primary
4 244GB 537GB 293GB primary

應該是有空間沒用到
從 cylinder 65271-97907 都沒用到
因為一般只允許四個 "primary" 分割區
最簡單方式是用 fdisk 將 /dev/sda4 砍掉，重割一個從 cylinder 29634-97907 的 sda4，然後 lvextend，再 resize2fs 填滿整個分割區即可

LVM可以隨時將新增空間併入，也可以隨時移除空間，只要你剩餘的空間足夠，被移除空間所存放的資料會移到別的空間所在的硬碟裡。但是不確定對於與MBR的對應位置是否也適用。