KVM 操作虚拟机常用命令

virsh list --all

virsh dominfo kvm-1

yum install virt-top -y
virt-top

virt-df kvm-1

virsh shutdown kvm-1

virsh start kvm-1

virsh autostart kvm-1

virsh autostart --disable kvm-1

virsh undefine kvm-1

virsh console kvm-1

virsh attach-disk kvm-1 /dev/sdb vbd --driver qemu --mode shareable

virsh detach-disk kvm vdb

[root@sh-kvm-1 ~]# lvcreate -n kvm-1-data -L 50G vg_shkvm1
[root@sh-kvm-1 ~]# virsh attach-disk kvm-1 /dev/vg_shkvm1/kvm-1-data vdb --driver qemu --mode shareable
Disk attached successfully
# 登录到kvm-1上查看lvm是否已经被挂载
[root@sh-kvm-1 ~]# virsh console kvm-1 # 输入kvm-1的用户和密码
[root@sh-kvm-1-1 ~]# fdisk -l # 查看硬盘挂载情况

Disk /dev/vda: 21.5 GB, 21474836480 bytes
16 heads, 63 sectors/track, 41610 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00058197

   Device Boot      Start         End      Blocks   Id  System
/dev/vda1   *           3        1018      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/vda2            1018       41611    20458496   8e  Linux LVM
Partition 2 does not end on cylinder boundary.

Disk /dev/mapper/VolGroup-lv_root: 18.8 GB, 18798870528 bytes
255 heads, 63 sectors/track, 2285 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: 0x00000000


Disk /dev/mapper/VolGroup-lv_swap: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 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: 0x00000000


Disk /dev/vdb: 53.7 GB, 53687091200 bytes  # 新添加的硬盘
16 heads, 63 sectors/track, 104025 cylinders
Units = cylinders of 1008 * 512 = 516096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

# 对新添加的硬盘分区
[root@sh-kvm-1-1 ~]# fdisk /dev/vdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0xf04b6807.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.

Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)

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): m  # 查看帮助
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)
Command (m for help): n  #添加一个分区
Command action
   e   extended
   p   primary partition (1-4)
p  #选择添加一个扩展分区
Partition number (1-4):
Value out of range.
Partition number (1-4): 1
First cylinder (1-104025, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-104025, default 104025):
Using default value 104025

Command (m for help): t  #改变分区的格式
Selected partition 1
Hex code (type L to list codes): 8e  #改成lvm
Changed system type of partition 1 to 8e (Linux LVM)

Command (m for help): w  # 保存更改
root@sh-kvm-1-1 ~]# mkfs.ext4 /dev/vdb1  # 格式化分区
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
3276800 inodes, 13107142 blocks
655357 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
400 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

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first.  Use tune2fs -c or -i to override.
[root@sh-kvm-1-1 ~]# pvc reate /dev/vdb1   # 创建pv
vdb   vdb1
[root@sh-kvm-1-1 ~]# vgextend VolGroup /dev/vdb  # 扩展lvm vg
vdb   vdb1
[root@sh-kvm-1-1 ~]# vgs
  VG       #PV #LV #SN Attr   VSize  VFree
  VolGroup   2   2   0 wz--n- 69.50g 50.00g
# 从上面能看出，新添加的 已经加到lvm组中

# 1. 查看虚拟机当前内存
[root@sh-kvm-1 ~]# virsh dominfo kvm-1 | grep memory
Max memory:     4194304 KiB
Used memory:    4194304 KiB

# 2、动态设置内存为512MB，内存减少
virsh setmem kvm-1 524288
# 注意单位必须是KB

# 3、查看内存变化
# virsh dominfo kvm-1 | grep memory
Max memory: 14194304 KiB
Used memory: 524288 kiB

# 4、内存增加
virsh shutdown kvm-1
virsh edit kvm-1  # 直接更改memory
virsh create /etc/libvirt/demu/kvm-1/xml
# 之后操作1,2,3步骤增加内存

virsh shutdown kvm-1
virsh edit kvm-1
#  <vcpu>2</vcpu>  # 4 > 2
virsh create /etc/libvirt/demu/kvm-1/xml

1. Create a 10-GB non-sparse file:
# dd if=/dev/zero of=/vm-images/vm1-add.img bs=1M count=10240
2. Shutdown the VM:
 # virsh shutdown vm1
3. Add an extra entry for ‘disk’ in the VM's XML file in /etc/libvirt/qemu. You can look copy & paste
the entry for your mail storage device and just change the target and address tags. For example:
 # virsh edit vm1
 <disk type='file' device='disk'>
 <driver name='qemu' type='raw' cache='none' io='threads'/>
 <source file='/vm-images/vm1.img'/>
 <target dev='vda' bus='virtio'/>
 <address type='pci' domain='0x0000' bus='0x00' slot='0x04'
function='0x0'/>
 </disk>
 Add:
 <disk type='file' device='disk'>
 <driver name='qemu' type='raw' cache='none' io='threads'/>
 <source file='/vm-images/vm1-add.img'/>
 <target dev='vdb' bus='virtio'/>
 <address type='pci' domain='0x0000' bus='0x00' slot='0x06'
function='0x0'/>
 </disk>
 # 这里建议使用上面的添加硬盘的方式添加

virsh shutdown kvm-1

virsh destroy kvm-1

virsh undefine kvm-1

 rm /dev/vg_shkvm1/kvm-1  # 不建议删除硬盘