虚拟机扩大硬盘

记录一下对vmware虚拟机扩大硬盘的过程。操作有风险，重要数据请先进行备份。

1、首先在vcenter中将虚拟机下电，然后编辑虚拟机，将虚拟机硬盘扩大。具体操作见下图 

2、打开虚拟机电源，利用fdisk -l可以看到虚拟机的硬盘变大了，但是df -h查看磁盘还是原来的。见下图 

root@demo:~# df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            997M  4.0K  997M   1% /dev
tmpfs           201M  692K  200M   1% /run
/dev/sda1       3.9G  1.6G  2.2G  42% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
none            5.0M     0  5.0M   0% /run/lock
none           1001M     0 1001M   0% /run/shm
none            100M     0  100M   0% /run/user
root@demo:~# fdisk -l

Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders, total 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00052d8e

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     8388607     4193280   83  Linux
/dev/sda2         8390654    12580863     2095105     5  Extended
/dev/sda5         8390656    12580863     2095104   82  Linux swap / Solaris
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3、利用fdisk命令扩大硬盘 
（本例子中计算sector号有误，把total 41943040 sectors当成了blocks来算的，导致扩大后/dev/sda2和/dev/sda5变小了。1个block应该对应多个sector。中间需要做一个换算。具体视自己系统而定）

root@demo:~# fdisk /dev/sda

Command (m for help): d
Partition number (1-5): 5

Command (m for help): d
Partition number (1-5): 2

Command (m for help): d
Selected partition 1

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-41943039, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): 37752831

Command (m for help): n
Partition type:
   p   primary (1 primary, 0 extended, 3 free)
   e   extended
Select (default p): e
Partition number (1-4, default 2): 2
First sector (37752832-41943039, default 37752832): 
Using default value 37752832
Last sector, +sectors or +size{K,M,G} (37752832-41943039, default 41943039): 39847936

Command (m for help): n
Partition type:
   p   primary (1 primary, 1 extended, 2 free)
   l   logical (numbered from 5)
Select (default p): l
Adding logical partition 5
First sector (37754880-39847936, default 37754880): 
Using default value 37754880
Last sector, +sectors or +size{K,M,G} (37754880-39847936, default 39847936): 
Using default value 39847936

Command (m for help): t
Partition number (1-5): 5
Hex code (type L to list codes): 82
Changed system type of partition 5 to 82 (Linux swap / Solaris)

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: 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.
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4、重启虚拟机后，利用resize2fs 扩大/dev/sda1

root@demo:~# resize2fs /dev/sda1
resize2fs 1.42.9 (4-Feb-2014)
Filesystem at /dev/sda1 is mounted on /; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 2
The filesystem on /dev/sda1 is now 4718848 blocks long.

root@demo:~# fdisk -l

Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders, total 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00052d8e

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048    37752831    18875392   83  Linux
/dev/sda2        37752832    39847936     1047552+   5  Extended
/dev/sda5        37754880    39847936     1046528+  82  Linux swap / Solaris
root@demo:~# df -h
Filesystem      Size  Used Avail Use% Mounted on
udev            997M   12K  997M   1% /dev
tmpfs           201M  684K  200M   1% /run
/dev/sda1        18G  1.6G   16G  10% /
none            4.0K     0  4.0K   0% /sys/fs/cgroup
none            5.0M     0  5.0M   0% /run/lock
none           1001M     0 1001M   0% /run/shm
none            100M     0  100M   0% /run/user
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5、重新建立逻辑分区

root@demo:~# mkswap /dev/sda5
Setting up swapspace version 1, size = 1046524 KiB
no label, UUID=5289e58e-730f-493b-844b-fdffe322c1f9
#将此步生成的UUID填入/etc/fstab
root@demo:~# swapon /dev/sda5

root@demo:~# vim /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda1 during installation
UUID=fabf2996-790a-40a1-ad4c-a3a9bf699f4c /               ext4    errors=remount-ro 0       1
# swap was on /dev/sda5 during installation
UUID=5289e58e-730f-493b-844b-fdffe322c1f9 none            swap    sw              0       0
/dev/fd0        /media/floppy0  auto    rw,user,noauto,exec,utf8 0       0
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6、重启虚拟机结束操作