linux扩展根分区详细步骤

213123

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：
[iyunv@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。
[iyunv@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：
[iyunv@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.
[iyunv@lub ~]#


--------------------使用命令发现partprobe /dev/sda3发现分区并没有起作用：
[iyunv@lub ~]# partprobe /dev/sda3
Error: Could not stat device /dev/sda3 - No such file or directory.
    [iyunv@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
[iyunv@lub ~]# pvcreate /dev/sda3
  Physical volume "/dev/sda3" successfully created
[iyunv@lub ~]# vgs
  VG       #PV #LV #SN Attr   VSize  VFree
  VolGroup   1   2   0 wz--n- 30.51g    0

[iyunv@lub ~]# vgextend VolGroup /dev/sda3
  Volume group "VolGroup" successfully extended
[iyunv@lub ~]# vgs
  VG       #PV #LV #SN Attr   VSize  VFree
  VolGroup   2   2   0 wz--n- 39.50g 8.99g

[iyunv@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

[iyunv@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：
[iyunv@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
[iyunv@lub ~]#

    完成扩展。！