备份数据
虽然说按照这个步骤做应该不会出什么问题, 但是重装系统毕竟是个麻烦事, 所以在扩容之前, 先做一下备份! 避免产生人品问题而后悔莫及. 毕竟备份虚拟机还是很省事的, 直接整个目录拷贝一份即可.
扩大VirtualDisk
我们先把VirtualBox里的这块硬盘扩大:
C:
cd "C:\Program Files\Oracle\VirtualBox"
VBoxManage modifyhd "D:\VM\mint-xfce\mint-xfce.vdi" --resize 1000000
正常的话, 系统会输出:
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
然后就退出了.
我们可以去VirtualBox里看看硬盘大小:
已经变成1000G了(其实我不小心多打了1个0, 不过无所谓了).
在Linux中创建新的分区
进入Linux, 切换为root用户, 运行fdisk -l:
chi-VirtualBox ~ # fdisk -l
Disk /dev/sda: 1048.6 GB, 1048576000000 bytes
255 heads, 63 sectors/track, 127482 cylinders, total 2048000000 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: 0x00067091
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 499711 248832 83 Linux
/dev/sda2 501758 83884031 41691137 5 Extended
/dev/sda5 501760 83884031 41691136 8e Linux LVM
Disk /dev/mapper/mint--vg-root: 40.5 GB, 40542142464 bytes
255 heads, 63 sectors/track, 4928 cylinders, total 79183872 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: 0x00000000
Disk /dev/mapper/mint--vg-root doesn't contain a valid partition table
Disk /dev/mapper/mint--vg-swap_1: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders, total 4194304 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: 0x00000000
Disk /dev/mapper/mint--vg-swap_1 doesn't contain a valid partition table
可以看到, 虽然硬盘的大小已经扩大了, 但是分区表还是没变. 所以现在我们去创建一个新的分区. 在我的Linux Mint里面有图形化界面可以创建, 所以我就不用fdisk了, 免得出错, 反正记得要 创建一个primary分区, 分区类型要选lvm(8e), 完成之后, 里面的分区应该是这样:
chi-VirtualBox ~ # fdisk -l
Disk /dev/sda: 1048.6 GB, 1048576000000 bytes
255 heads, 63 sectors/track, 127482 cylinders, total 2048000000 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: 0x00067091
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 499711 248832 83 Linux
/dev/sda2 501758 83884031 41691137 5 Extended
/dev/sda3 83886080 2047999999 982056960 8e Linux LVM
/dev/sda5 501760 83884031 41691136 8e Linux LVM
Disk /dev/mapper/mint--vg-root: 40.5 GB, 40542142464 bytes
255 heads, 63 sectors/track, 4928 cylinders, total 79183872 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: 0x00000000
Disk /dev/mapper/mint--vg-root doesn't contain a valid partition table
Disk /dev/mapper/mint--vg-swap_1: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders, total 4194304 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: 0x00000000
Disk /dev/mapper/mint--vg-swap_1 doesn't contain a valid partition table
其中/dev/sda3是我们新创建的分区.
创建和扩展lvm分区
扩大volume group
由于使用了lvm, 我们可以方便的扩展已有分区. 首先查看已有的volume group:
chi-VirtualBox ~ # vgdisplay
--- Volume group ---
VG Name mint-vg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 39.76 GiB
PE Size 4.00 MiB
Total PE 10178
Alloc PE / Size 10178 / 39.76 GiB
Free PE / Size 0 / 0
VG UUID aR8Gl4-toof-YxoL-Jo2L-X8it-wfEe-B1YxUF
可以看到, 已有一个volume group, 我们可以把/dev/sda3加到这个volume group里面:
chi-VirtualBox ~ # vgextend mint-vg /dev/sda3
No physical volume label read from /dev/sda3
Writing physical volume data to disk "/dev/sda3"
Physical volume "/dev/sda3" successfully created
Volume group "mint-vg" successfully extended
我们再看看volume group的情况:
chi-VirtualBox ~ # vgdisplay
--- Volume group ---
VG Name mint-vg
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 976.32 GiB
PE Size 4.00 MiB
Total PE 249937
Alloc PE / Size 10178 / 39.76 GiB
Free PE / Size 239759 / 936.56 GiB
VG UUID aR8Gl4-toof-YxoL-Jo2L-X8it-wfEe-B1YxUF
可以看到, 原来的volume group已经被我们扩大到了976.32GB.
扩大 logical volume
首先, 我们查看目前的logical Volume:
chi-VirtualBox ~ # lvdisplay
--- Logical volume ---
LV Path /dev/mint-vg/root
LV Name root
VG Name mint-vg
LV UUID 2hNBQf-1zGs-3nZF-4feA-uR9W-WVDQ-32lLm4
LV Write Access read/write
LV Creation host, time mint, 2013-07-23 09:26:24 +0800
LV Status available
# open 1
LV Size 37.76 GiB
Current LE 9666
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:0
--- Logical volume ---
LV Path /dev/mint-vg/swap_1
LV Name swap_1
VG Name mint-vg
LV UUID fD6Mwy-IYEy-ZxXN-aPPW-WNn7-catg-o1bRsX
LV Write Access read/write
LV Creation host, time mint, 2013-07-23 09:26:24 +0800
LV Status available
# open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:1
可以看到, 系统中只有一个logical Volume, 它是/root的挂载点. 我们现在要做的就是将这个logical volume 扩大. 在logical volume扩大时, 会自动使用volume group中的空间.
chi-VirtualBox ~ # lvextend -L 100G /dev/mint-vg/root
Extending logical volume root to 100.00 GiB
Logical volume root successfully resized
chi-VirtualBox ~ # lvdisplay
--- Logical volume ---
LV Path /dev/mint-vg/root
LV Name root
VG Name mint-vg
LV UUID 2hNBQf-1zGs-3nZF-4feA-uR9W-WVDQ-32lLm4
LV Write Access read/write
LV Creation host, time mint, 2013-07-23 09:26:24 +0800
LV Status available
# open 1
LV Size 100.00 GiB
Current LE 25600
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:0
--- Logical volume ---
LV Path /dev/mint-vg/swap_1
LV Name swap_1
VG Name mint-vg
LV UUID fD6Mwy-IYEy-ZxXN-aPPW-WNn7-catg-o1bRsX
LV Write Access read/write
LV Creation host, time mint, 2013-07-23 09:26:24 +0800
LV Status available
# open 2
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 252:1
可以看到, logical volume 已经成功的变大为了100GB.
扩大ext4分区
最后一步, 我们需要把logical volume上的ext4分区也扩大, 这样才能真正的存下文件.
chi-VirtualBox ~ # resize2fs /dev/mint-vg/root
resize2fs 1.42.5 (29-Jul-2012)
Filesystem at /dev/mint-vg/root is mounted on /; on-line resizing required
old_desc_blocks = 3, new_desc_blocks = 7
The filesystem on /dev/mint-vg/root is now 26214400 blocks long.
chi-VirtualBox ~ # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/mint--vg-root 99G 26G 69G 28% /
none 4.0K 0 4.0K 0% /sys/fs/cgroup
udev 985M 4.0K 985M 1% /dev
tmpfs 201M 896K 200M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 1002M 72K 1002M 1% /run/shm
none 100M 16K 100M 1% /run/user
/dev/sda1 228M 75M 141M 35% /boot
可以看到/下面的空间已经成功扩大了.
关于lvm的一些知识…
相信看了上面的步骤你已经和我一样晕了…下面我来试图解释一下lvm中的各种术语
- 首先是volume group, 这个你可以想成是扩展分区, 不同的是volume group可以跨多块硬盘多个设备(这是lvm的牛逼之处), 用
vgdisplay可以查看. - 然后是physical volume, 这个就是传统意义上的分区, 例如/dev/sda5, 用
pvdisplay可以查看 - 然后是logical volume, 这个就是lvm中的逻辑分区, 地位相当于逻辑分区. 你硬盘上的目录, 就是挂载在logical volume上的. 用
lvdisplay可以查看.
lvm有什么好处?
简单的讲, 就是你可以分出多个物理上的逻辑分区(例如 /dev/sda1 - /dev/sda5), 然后把它们放到同一个volume group中, 再从volume group中划分出不同的logical volume, 用于不同目录的挂载. 这样, 相当于在物理上的逻辑分区之上又抽象出了新的逻辑分区, 新的逻辑分区可以任意变化大小, 甚至可以横跨不同的硬盘, 非常灵活.
一句话总结一下: 用fdisk创建physical volume, physical volume 组成 volume group, volume group划分为若干logical volume, 目录挂载在logical volume之上.