Linux虚拟机扩展根分区！

虚拟机根分区空间不够用，在虚拟机管理界面进行单个磁盘扩展(图形化界面操作略)，比如原来是30G，扩展至40G，(扩展需要关机之后操作)

其中的10G空间需要重新分区，以下是分区相关操作让扩展的空间生效：

登录系统之后：

df -h  发现空间没有发生变化：

[root@lub ~]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root

25G   19G  4.2G  82% /

tmpfs                 642M     0  642M   0% /dev/shm

/dev/sda1             485M   34M  426M   8% /boot

fdisk -l   发现总容量已经扩展。

[root@lub ~]# fdisk -l

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 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: 0x00069f1c

------------------------------

对扩展的磁盘进行分区：

[root@lub ~]# fdisk /dev/sda

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to

switch off the mode (command 'c') and change display units to

sectors (command 'u').

Command (m for help): p

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 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: 0x00069f1c

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        4047    31992832   8e  Linux LVM

Command (m for help): n

Command action

e   extended

p   primary partition (1-4)

3

Invalid partition number for type `3'

Command action

e   extended

p   primary partition (1-4)

p

Partition number (1-4): 3

First cylinder (4047-5221, default 4047):

Using default value 4047

Last cylinder, +cylinders or +size{K,M,G} (4047-5221, default 5221):

Using default value 5221

Command (m for help): p -------查看分区后的情况

Disk /dev/sda: 42.9 GB, 42949672960 bytes

255 heads, 63 sectors/track, 5221 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: 0x00069f1c

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        4047    31992832   8e  Linux LVM

/dev/sda3            4047        5221     9431826+  83  Linux

---新增的sda3

Command (m for help): w  保存分区

The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.

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)

Syncing disks.

[root@lub ~]#

--------------------使用命令发现partprobe /dev/sda3发现分区并没有起作用：

[root@lub ~]# partprobe /dev/sda3

Error: Could not stat device /dev/sda3 - No such file or directory.

[root@lub ~]# pvcreate /dev/sda3

Device /dev/sda3 not found (or ignored by filtering).

-----重启系统。

------LVM操作。扩展根分区

[root@lub ~]# pvcreate /dev/sda3

Physical volume "/dev/sda3" successfully created

[root@lub ~]# vgs

VG       #PV #LV #SN Attr   VSize  VFree

VolGroup   1   2   0 wz--n- 30.51g    0

[root@lub ~]# vgextend VolGroup /dev/sda3

Volume group "VolGroup" successfully extended

[root@lub ~]# vgs

VG       #PV #LV #SN Attr   VSize  VFree

VolGroup   2   2   0 wz--n- 39.50g 8.99g

[root@lub ~]# lvextend -L +8.99G /dev/mapper/VolGroup-lv_root

Rounding size to boundary between physical extents: 8.99 GiB

Extending logical volume lv_root to 33.50 GiB

Logical volume lv_root successfully resized

[root@lub ~]# resize2fs /dev/mapper/VolGroup-lv_root

resize2fs 1.41.12 (17-May-2010)

Filesystem at /dev/mapper/VolGroup-lv_root is mounted on /; on-line resizing required

old desc_blocks = 2, new_desc_blocks = 3

Performing an on-line resize of /dev/mapper/VolGroup-lv_root to 8781824 (4k) blocks.

The filesystem on /dev/mapper/VolGroup-lv_root is now 8781824 blocks long.

----命令操作根分区情况，发现已经生效：

[root@lub ~]# df -h

Filesystem            Size  Used Avail Use% Mounted on

/dev/mapper/VolGroup-lv_root

33G   19G   13G  60% /

tmpfs                 642M     0  642M   0% /dev/shm

/dev/sda1             485M   34M  426M   8% /boot

[root@lub ~]#

完成扩展。！