kvm-虚拟机增加硬盘空间
kvm虚拟化模式下，给虚拟机增加硬盘空间概念上有3种办法；首先执行指令：virsh resize VR.img +2G
其中方法一，可参考http://geekpeek.net/resize-filesystem-fdisk-resize2fs/，及动态扩充非lvm磁盘空间，此处不可行的原因在于扩充需要卸载挂载点，而根节点或者boot节点不可卸载，否则会出问题；
方法一：fdisk模式下直接将新增磁盘空间给予/，及根挂载点；
方法二：fdisk模式下，将新增磁盘空间成为一个新的分区，如/dev/sda3，然后mkfs -t ext4 /dev/sda3，然后挂载到某一目录；
方法三：将新增磁盘空间成为一个新的磁盘；具体方法参照http://blog.fens.me/vps-kvm-disk/；概括如下：
1. host增加物理硬盘并分区
HOST作为KVM的宿主计算机，管理所有GUEST虚拟机。我们通过给HOST增加物理硬盘，然后分给GUEST，从而实现给虚拟机硬盘扩容的效果。
如何给计算机增加物理硬盘并分区，请参考：多硬盘分区管理fdisk 文章
查看HOST机的硬盘
~ sudo fdisk -l
Disk /dev/sda: 299.4 GB, 299439751168 bytes
255 heads, 63 sectors/track, 36404 cylinders, total 584843264 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: 0x000efd7c
Device Boot Start End Blocks Id System
/dev/sda1 2048 97656831 48827392 82 Linux swap / Solaris
/dev/sda2 97656832 136718335 19530752 83 Linux
/dev/sda3 136718336 214843335 39062500 83 Linux
/dev/sda4 * 214843392 215037951 97280 83 Linux
Disk /dev/sdb: 1999.3 GB, 1999307276288 bytes
255 heads, 63 sectors/track, 243068 cylinders, total 3904897024 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: 0xf919a976
Device Boot Start End Blocks Id System
/dev/sdb1 2048 1952448511 976223232 7 HPFS/NTFS/exFAT
/dev/sdb2 1952448512 3904897023 976224256 5 Extended
/dev/sdb5 1952450560 2267023360 157286400+ 83 Linux
/dev/sdb6 2267025409 2581596160 157285376 83 Linux
/dev/sdb7 2581598209 2896168960 157285376 83 Linux
/dev/sdb8 2896171009 3210741760 157285376 83 Linux
/dev/sdb9 3210743809 3525314560 157285376 83 Linux
/dev/sdb10 3525316609 3904897023 189790207+ 83 Linux
~ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 37G 3.4G 32G 10% /
udev 24G 4.0K 24G 1% /dev
tmpfs 9.5G 1.1M 9.5G 1% /run
none 5.0M 8.0K 5.0M 1% /run/lock
none 24G 152K 24G 1% /run/shm
none 100M 28K 100M 1% /run/user
cgroup 24G 0 24G 0% /sys/fs/cgroup
/dev/sda2 19G 3.6G 14G 21% /home
/dev/sda4 92M 34M 54M 39% /boot
/dev/sdb1 931G 100G 832G 11% /disk/sdb1
/dev/sdb6 148G 188M 140G 1% /disk/sdb6
下面将进行两个测试：
通过virsh给guest增加文件硬盘：通过文件硬盘的镜像/disk/sdb6/c1d6.img
通过virsh给guest增加分区硬盘：直接使用分区硬盘/dev/sdb5
2. 通过virsh给guest增加文件硬盘
创建文件硬盘的镜像
~ cd /disk/sdb6/
~ sudo qemu-img create -f raw /disk/sdb6/c1d6.img 10G
Formatting '/disk/sdb6/c1d6.img', fmt=raw size=10737418240
~ ls -l
-rw-r--r-- 1 root root 10737418240 Jul 8 16:37 c1d6.img
drwx------ 2 root root 16384 Jul 8 09:03 lost+found/
通过virsh管理工具加载硬盘
~ sudo virsh
Welcome to virsh, the virtualization interactive terminal.
Type: 'help' for help with commands
'quit' to quit
#查看系统内的虚拟机
virsh # list
Id Name State
----------------------------------------------------
5 server3 running
6 server4 running
7 d2 running
8 r1 running
9 server2 running
12 c1 running
#在这里我们要对c1进行硬盘扩容
virsh # edit c1
#找到硬盘配置(原来的系统硬盘)
<disk type='file' device='disk'>
<driver name='qemu' type='raw'/>
<source file='/disk/sdb1/c1.img'/>
<target dev='vda' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
</disk>
#增加文件硬盘,vdb
<disk type='file' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source file='/disk/sdb6/c1d6.img'/>
<target dev='vdb' bus='virtio'/>
<address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
</disk>
#保存退出
重启c1虚拟机
#请使用destroy命令，reboot和shutdown不管用。
~ virsh # destroy c1
Domain c1 destroyed
#list找不到c1
~ virsh # list
Id Name State
----------------------------------------------------
5 server3 running
6 server4 running
7 d2 running
8 r1 running
9 server2 running
#启动虚拟机c1
~ virsh # start c1
Domain c1 started
#进入虚拟机c1
~ console c1
在c1中，进行硬盘查检并分区
~ sudo fdisk -l
Disk /dev/vda: 42.9 GB, 42949672960 bytes
16 heads, 63 sectors/track, 83220 cylinders, total 83886080 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: 0x000516aa
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 499711 248832 83 Linux
/dev/vda2 501758 83884031 41691137 5 Extended
/dev/vda5 501760 83884031 41691136 8e Linux LVM
Disk /dev/vdb: 10.7 GB, 10737418240 bytes
16 heads, 63 sectors/track, 20805 cylinders, total 20971520 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/vdb doesn't contain a valid partition table
Disk /dev/mapper/u1210-root: 38.4 GB, 38394658816 bytes
255 heads, 63 sectors/track, 4667 cylinders, total 74989568 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/u1210-root doesn't contain a valid partition table
Disk /dev/mapper/u1210-swap_1: 4294 MB, 4294967296 bytes
255 heads, 63 sectors/track, 522 cylinders, total 8388608 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/u1210-swap_1 doesn't contain a valid partition table
/dev/vdb已经被识别，接下来 分区,格式化,挂载,使用
硬盘分区
~ sudo fdisk /dev/vdb
Command (m for help): p
Disk /dev/vdb: 161.1 GB, 161061274112 bytes
16 heads, 63 sectors/track, 312076 cylinders, total 314572801 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: 0x3b49c6a0
Device Boot Start End Blocks Id System
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):
Using default value 1
First sector (2048-314572800, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-314572800, default 314572800):
Using default value 314572800
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
#分区生效
~ sudo partprobe
~ sudo fdisk -l
Disk /dev/vdb: 10.7 GB, 10737418240 bytes
2 heads, 17 sectors/track, 616809 cylinders, total 20971520 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: 0xf0432cd6
Device Boot Start End Blocks Id System
/dev/vdb1 2048 20971519 10484736 83 Linux
格式化
~ sudo mkfs -t ext4 /dev/vdb1
mke2fs 1.42.5 (29-Jul-2012)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
9830400 inodes, 39321344 blocks
1966067 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
1200 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
挂载
~ sudo mount /dev/vdb1 /home/cos/hadoopb
~ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/u1210-root 36G 1.1G 33G 4% /
udev 2.0G 4.0K 2.0G 1% /dev
tmpfs 791M 232K 791M 1% /run
none 5.0M 0 5.0M 0% /run/lock
none 2.0G 0 2.0G 0% /run/shm
none 100M 0 100M 0% /run/user
/dev/vda1 228M 29M 188M 14% /boot
/dev/vdb1 9.9G 151M 9.2G 2% /home/cos/hadoopb
使用
/home/cos/hadoopb的目录，已经挂载到了/dev/vdb1上面，我可以在hadoopb下载做任何的操作。
3. 通过virsh给guest增加分区硬盘
直接使用HOST的分区硬盘/dev/sdb5，做个虚拟机c1的分区
virsh # edit c1
#新增新硬盘vbc
<disk type='block' device='disk'>
<driver name='qemu' type='raw' cache='none'/>
<source dev='/dev/sdb5'/>
<target dev='vbc' bus='virtio'/>
</disk>
virsh # destroy c1
Domain c1 destroyed
virsh # start c1
Domain c1 started
virsh # console c1
登陆虚拟c1，查看硬盘信息
sudo fdisk -l
[sudo] password for cos:
Disk /dev/vda: 42.9 GB, 42949672960 bytes
16 heads, 63 sectors/track, 83220 cylinders, total 83886080 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: 0x000516aa
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 499711 248832 83 Linux
/dev/vda2 501758 83884031 41691137 5 Extended
/dev/vda5 501760 83884031 41691136 8e Linux LVM
Disk /dev/vdb: 10.7 GB, 10737418240 bytes
2 heads, 17 sectors/track, 616809 cylinders, total 20971520 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: 0xf0432cd6
Device Boot Start End Blocks Id System
/dev/vdb1 2048 20971519 10484736 83 Linux
Disk /dev/vdc: 161.1 GB, 161061274112 bytes
4 heads, 4 sectors/track, 19660800 cylinders, total 314572801 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: 0x3b49c6a0
Device Boot Start End Blocks Id System
/dev/vdc1 2048 314572800 157285376+ 83 Linux
Disk /dev/mapper/u1210-root: 38.4 GB, 38394658816 bytes
255 heads, 63 sectors/track, 4667 cylinders, total 74989568 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/u1210-root doesn't contain a valid partition table
Disk /dev/mapper/u1210-swap_1: 4294 MB, 4294967296 bytes
255 heads, 63 sectors/track, 522 cylinders, total 8388608 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/u1210-swap_1 doesn't contain a valid partition table
已经被正确识别
Disk /dev/vdc: 161.1 GB, 161061274112 bytes
接下来，可以参考上面类似的过程，分区，格式化，挂载，使用。
现将http://geekpeek.net/resize-filesystem-fdisk-resize2fs/方法复制如下：
There was a question in my post on “Linux partitioning with fdisk on CentOS 6“. Our reader asked if it is possible to extend an existing linux non LVM partition without loosing it’s data … here is a post on how to resizepartition and filesystem with fdisk and resize2fs.
IMPORTANT: In order to resize partition (extend), enough disk space must be available! We can not extend a partition if there are no free sectors/cylinders at the end of the partition to extend!
PLEASE BACKUP YOUR DATA BEFORE RESIZING ANY PARTITION! GeekPeek.Net is not responsible for any data loss!
Resize Partition and Filesystem with fdisk and resize2fs
Let’s Resize Partition and Filesystem with fdisk and resize2fs!
Our system has two disks:
- /dev/sda – 16GB system disk with LVM partitions (root and swap)
- /dev/sdb – 1GB clean disk for tutorial purpose
For the start of this tutorial tutorial we have created one partition on /dev/sdb disk.Partition size (/dev/sdb1) is 500MB. We created an ext4 filesystem on this partition and put some dummy data on it. We will be modifying our partitions with fdisk and filesystem with resize2fs.
For more information on how to create and modify partitions with fdisk read “Linux partitioning with fdisk on CentOS 6“.
Extend Partition and Filesystem
Before we start, let’s check the current disk configuration. Geekpeek mount point is the partition we want to extend. We can see that the partition has 494MB of available space and 401MB is already used by dummy data. We want to extend the partition to 1GB:
[root@foo1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_foo-LogVol01
13G 4.6G 7.7G 38% /
tmpfs 376M 0 376M 0% /dev/shm
/dev/sda1 485M 105M 355M 23% /boot
/dev/sdb1 494M 402M 67M 86% /geekpeek
1. Unmount the partition
[root@foo1 ~]# umount /geekpeek/ [root@foo1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_foo-LogVol01 13G 4.6G 7.7G 38% / tmpfs 376M 0 376M 0% /dev/shm /dev/sda1 485M 105M 355M 23% /boot
2. Delete the partition
[root@foo1 ~]# fdisk /dev/sdb 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): d Selected partition 1 Command (m for help): p Disk /dev/sdb: 1073 MB, 1073741824 bytes 255 heads, 63 sectors/track, 130 cylinders, total 2097152 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: 0x2dbb9f13 Device Boot Start End Blocks Id System Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
3. Create a new (larger) partition
[root@foo1 ~]# fdisk /dev/sdb
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): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First sector (2048-2097151, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-2097151, default 2097151):
Using default value 2097151
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 cylinders, total 2097152 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: 0x2dbb9f13
Device Boot Start End Blocks Id System
/dev/sdb1 2048 2097151 1047552 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
We are able to mount the partition at this point, but the filesystem on this partition is only 500MB large. We need to resize the filesystem using resize2fs command in the following steps.
4. Run fsck on your filesystem
[root@foo1 ~]# e2fsck -f /dev/sdb1 e2fsck 1.41.12 (17-May-2010) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/sdb1: 16/130560 files (0.0% non-contiguous), 426988/522080 blocks
5. Resize your filesystem with resize2fs
[root@foo1 ~]# resize2fs /dev/sdb1 resize2fs 1.41.12 (17-May-2010) Resizing the filesystem on /dev/sdb1 to 1044192 (1k) blocks. The filesystem on /dev/sdb1 is now 1044192 blocks long.
6. Re-mount extended partition
[root@foo1 ~]# mount /dev/sdb1 /geekpeek/ [root@foo1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_foo-LogVol01 13G 4.6G 7.7G 38% / tmpfs 376M 0 376M 0% /dev/shm /dev/sda1 485M 105M 355M 23% /boot /dev/sdb1 988M 402M 536M 43% /geekpeek
Voila! The partition was successfully extended, as we can see all of the data survived! Always remember to resize the filesystem with resize2fs.
Reduce a Partition and Filesystem
Reviewing the current disk configuration: Geekpeek mount point is the partition we want to reduce. We can see that the partition has 988MB of available space and 324MB is used by dummy data. We want to reduce the partition to 400MB without loosing data:
[root@foo1 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_foo-LogVol01
13G 4.6G 7.7G 38% /
tmpfs 376M 0 376M 0% /dev/shm
/dev/sda1 485M 105M 355M 23% /boot
/dev/sdb1 988M 324M 614M 35% /geekpeek
1. Unmount the partition
[root@foo1 ~]# umount /geekpeek/ [root@foo1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_foo-LogVol01 13G 4.6G 7.7G 38% / tmpfs 376M 0 376M 0% /dev/shm /dev/sda1 485M 105M 355M 23% /boot
2. Run fsck on your filesystem
[root@foo1 ~]# e2fsck -f /dev/sdb1 e2fsck 1.41.12 (17-May-2010) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/sdb1: 15/261120 files (0.0% non-contiguous), 363953/1044192 blocks
3. Resize the filesystem with resize2fs
[root@foo1 ~]# resize2fs /dev/sdb1 400M resize2fs 1.41.12 (17-May-2010) Resizing the filesystem on /dev/sdb1 to 409600 (1k) blocks. The filesystem on /dev/sdb1 is now 409600 blocks long.
4. Delete the partition
[root@foo1 ~]# fdisk /dev/sdb 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): d Selected partition 1 Command (m for help): p Disk /dev/sdb: 1073 MB, 1073741824 bytes 255 heads, 63 sectors/track, 130 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: 0x2dbb9f13 Device Boot Start End Blocks Id System Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks.
4. Create a new (smaller) partition
[root@foo1 ~]# fdisk /dev/sdb
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): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-130, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-130, default 130): +400M
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 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: 0x2dbb9f13
Device Boot Start End Blocks Id System
/dev/sdb1 1 52 417658+ 83 Linux
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
5. Mount the new partition and filesystem
[root@foo1 ~]# mount /dev/sdb1 /geekpeek/ [root@foo1 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_foo-LogVol01 13G 4.6G 7.7G 38% / tmpfs 376M 0 376M 0% /dev/shm /dev/sda1 485M 105M 355M 23% /boot /dev/sdb1 388M 323M 45M 88% /geekpeek
Voila! The partition was successfully reduced to 400MB, as we can see all of the data survived! Always remember to resize the filesystem with resize2fs.