通过qemu-nbd方式挂载qcow2镜像格式

通过qemu-nbd方式挂载qcow2镜像格式 

 

一、查看NBD（Network Block Device）信息

[root@localhost ~]# modinfo nbd
filename:       /lib/modules/3.11.10-301.fc20.x86_64/kernel/drivers/block/nbd.ko
license:        GPL
description:    Network Block Device
depends:        
intree:         Y
vermagic:       3.11.10-301.fc20.x86_64 SMP mod_unload 
signer:         Fedora kernel signing key
sig_key:        03:59:1D:C5:7A:69:07:41:40:1A:1C:20:2E:2B:3D:9F:4F:ED:2A:0E
sig_hashalgo:   sha256
parm:           nbds_max:number of network block devices to initialize (default: 16) (int)
parm:           max_part:number of partitions per device (default: 0) (int)
parm:           debugflags:flags for controlling debug output (int)
[root@localhost ~]# modprobe nbd max_part=16
[root@localhost ~]# lsmod | grep nbd
nbd                    17554  0 

二、将qcow2镜像映射为网络设备（NBD）

[root@localhost ~]# qemu-nbd -c /dev/n
nbd0                nbd11               nbd14               nbd3                nbd6                nbd9                network_throughput
nbd1                nbd12               nbd15               nbd4                nbd7                net/                null
nbd10               nbd13               nbd2                nbd5                nbd8                network_latency     nvram
[root@localhost ~]# qemu-nbd -c /dev/nbd0 /var/lib/libvirt/images/ubuntu.img 
[root@localhost ~]# ll /dev/nbd0*
brw-rw----. 1 root disk 43, 0 Jun 23 15:16 /dev/nbd0
brw-rw----. 1 root disk 43, 1 Jun 23 15:16 /dev/nbd0p1
brw-rw----. 1 root disk 43, 2 Jun 23 15:16 /dev/nbd0p2
brw-rw----. 1 root disk 43, 5 Jun 23 15:16 /dev/nbd0p5

三、挂载qcow2镜像中的分区

 

[root@localhost ~]# mount /dev/nbd0p1 /imgage/
[root@localhost ~]# ll /imgage/
total 92
drwxr-xr-x.  2 root root  4096 May 27 08:53 bin
drwxr-xr-x.  3 root root  4096 May 27 08:59 boot
drwxr-xr-x.  3 root root  4096 May 26 18:24 dev
drwxr-xr-x. 89 root root  4096 Jun 23 14:48 etc
drwxr-xr-x.  3 root root  4096 May 27 08:59 home
lrwxrwxrwx.  1 root root    33 May 26 18:25 initrd.img -> boot/initrd.img-3.13.0-24-generic
drwxr-xr-x. 21 root root  4096 May 27 08:53 lib
drwxr-xr-x.  2 root root  4096 May 26 18:24 lib64
drwx------.  2 root root 16384 May 26 18:24 lost+found
drwxr-xr-x.  3 root root  4096 May 26 18:24 media
drwxr-xr-x.  2 root root  4096 Apr 11 06:12 mnt
drwxr-xr-x.  2 root root  4096 Apr 17 05:02 opt
drwxr-xr-x.  2 root root  4096 Apr 11 06:12 proc
drwx------.  3 root root  4096 May 27 09:28 root
drwxr-xr-x.  2 root root  4096 May 27 09:07 run
drwxr-xr-x.  2 root root  4096 May 27 09:07 sbin
drwxr-xr-x.  2 root root  4096 Apr 17 05:02 srv
drwxr-xr-x.  2 root root  4096 Mar 13 09:41 sys
drwxrwxrwt.  2 root root  4096 Jun 23 15:17 tmp
drwxr-xr-x. 10 root root  4096 May 26 18:24 usr
drwxr-xr-x. 12 root root  4096 May 27 08:55 var
lrwxrwxrwx.  1 root root    30 May 26 18:25 vmlinuz -> boot/vmlinuz-3.13.0-24-generic

四、umount分区，接触qcow2与nbd设备的关联

 

[root@localhost ~]# umount /imgage 
[root@localhost ~]# qemu-nbd -d /dev/nbd0
/dev/nbd0 disconnected