/bin/dd if=/path/to/source-file of=/path/to/backup-file

[root@ok virhost]# qemu-img info 05t.img
image: 05t.img
file format: raw
virtual size: 10G (10737418240 bytes)
disk size: 1.7G
[root@ok virhost]# ll -h 05t.img
-rwxr-xr-x. 1 root root 10G Jun 26 17:46 05t.img

[root@ok virhost]# ll -h 05t.img
-rwxr-xr-x. 1 root root 10G Jun 26 17:46 05t.img

[root@ok virhost]# /bin/dd if=/dev/cdrom of=/iso/centos64.iso#拷贝镜像

[root@bass virhost]# /bin/dd if=./05cache.img of=./05cache.img.bak
20971520+0 records in
20971520+0 records out
10737418240 bytes (11 GB) copied, 133.78 s, 80.3 MB/s

[root@ok virhost]# virt-install --virt-type kvm --name kvm-demo-07 --ram 512 --cdrom=/home/ISO/CentOS-6.7-x86_64-bin-DVD1.iso --network network=default --vnclisten=0.0.0.0 --vncport=6007 --noautoconsole --disk path=/home/virhost/kvm-demo-07.img,size=10

+++++++++++++++++++++服务器+++++++++++++++++++++++++++

[root@chesi ~]# cat /proc/cpuinfo |grep name |cut -f2 -d: |uniq -c
     16  Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz

[root@chesi ~]# free -h
             total       used       free     shared    buffers     cached
Mem:           15G        11G       3.5G        35M       260M       401M
-/+ buffers/cache:        11G       4.2G
Swap:         2.0G         0B       2.0G

R730 有 4个千兆网口