參考：https://www.cnblogs.com/superlinux/p/11923739.html
http://blog.chinaunix.net/uid-29847640-id-5752497.html
剛建不久的日誌服務器管理頁面打不開了，進入linux發現要目錄已沒有空間了，操作好命令都沒反應，只得進行磁盤擴容操作。
root@NAIC-CVK10:/local_space# qemu-img info rzfwq2
root@NAIC-CVK10:/local_space# virsh list --all
root@NAIC-CVK10:/local_space# virsh stop rzfwq2
root@NAIC-CVK10:/local_space# qemu-img resize rzfwq2 +30G
Image resized.
root@NAIC-CVK10:/local_space# qemu-img info rzfwq2
image: rzfwq2
file format: qcow2
virtual size: 130G (139586437120 bytes)
disk size: 91G
cluster_size: 262144
Format specific information:
compat: 1.1
lazy refcounts: false
refcount bits: 16
corrupt: false
[root@logserver2 ~]# fdisk /dev/vda
Command (m for help): p
Disk /dev/vda: 139.6 GB, 139586437120 bytes
16 heads, 63 sectors/track, 270466 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000b3f08
Device Boot Start End Blocks Id System
/dev/vda1 * 3 1018 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2 1018 208051 104344576 8e Linux LVM
Partition 2 does not end on cylinder boundary.
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (1-270466, default 1): 208051
Last cylinder, +cylinders or +size{K,M,G} (208051-270466, default 270466):
Using default value 270466
Command (m for help): t
Partition number (1-4): 3
Hex code (type L to list codes): 8e
Changed system type of partition 3 to 8e (Linux LVM)
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: 設備或資源忙.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
[root@logserver2 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
VolGroup 2 2 0 wz--n- 129.50g 30.00g
data_vg 1 1 0 wz--n- 1.56t 600.00g
[root@logserver2 ~]# vgextend VolGroup /dev/vda3
Volume group "VolGroup" successfully extended
You have mail in /var/spool/mail/root
[root@logserver2 ~]# lvs
LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert
lv_root VolGroup -wi-ao---- 91.70g
lv_swap VolGroup -wi-ao---- 7.81g
log_lv data_vg -wi-ao---- 1000.00g
[root@logserver2 ~]# vgdisplay
--- Volume group ---
VG Name VolGroup
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 129.50 GiB
PE Size 4.00 MiB
Total PE 33153
Alloc PE / Size 25474 / 99.51 GiB
Free PE / Size 7679 / 30.00 GiB
VG UUID 7soJlX-Cc0t-P3Ul-ZCKI-foxN-nzXO-Quksg2
[root@logserver2 ~]# lvextend -r -l +7679 /dev/mapper/VolGroup-lv_root
Extending logical volume lv_root to 121.69 GiB
Logical volume lv_root successfully resized
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/VolGroup-lv_root is mounted on /; on-line resizing required
old desc_blocks = 6, new_desc_blocks = 8
Performing an on-line resize of /dev/mapper/VolGroup-lv_root to 31900672 (4k) blocks.
The filesystem on /dev/mapper/VolGroup-lv_root is now 31900672 blocks long.