last update: 22-8-11
 

User mode
    qemu linux.img

System mode
    qemu-i386 -L / /bin/ls

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apt-get install qemu qemu-utils

qemu
qemu-img
 

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建立 image

 

qemu-img create -f qcow2 hda.img 10G 

Default cluster_size: 65536

 

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啟動

 

qemu -hda c.img -cdrom linux.iso -boot d -m 128 -localtime -vnc,password -monitor stdio

 

-monitor stdio 在 cmd mode 下見到 monitor

-boot [a|b|c|d]
a|b: floppy
c: 硬硬 (default)
d: CD-ROM

-localtime
預設上是使用 UTC 時間

(qemu) change vnc password
Password: ********
(qemu)

 

(qemu) info vnc

Server:
     address: 0.0.0.0:5900
        auth: vnc
Client: none
(qemu) info vnc
Server:
     address: 0.0.0.0:5900
        auth: vnc
Client:
     address: 192.168.123.21:1478
  x509_dname: none
    username: none

 

 

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QEMU Monitor

 

• info
• change

 

Ctrl-Alt-n

• 1   Target system display
• 2   Monitor
• 3   Serial port

Ctrl-a c
           Switch between console and monitor

info
screendump filename

commit device|all -- commit changes to the disk images (if -snapshot is used) or backing files

change device filename
savevm filename
loadvm filename

stop
cont
sendkey
system_reset
quit

 

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網路

-nics n
-n script
    /etc/qemu-ifup
-user-net
    default
-dummy-net

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VMwave To qemu

qemu-img convert -f vmdk ./sata-d0.vmdk debian6.master.qcow2

Default 的 output fmt 是 raw !!!

如果要設定 Format 的話, 就要加上 -O output_fmt

強烈建議用 qcow2, 因為它支援

• backing_file
• encryption
• cluster_size
• preallocation
• compression
• snapshots

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查看 Image 資訊

qemu-img info debian6.master.qcow2

image: debian6.master.qcow2
file format: raw
virtual size: 2.0G (2147483648 bytes)
disk size: 971M

 

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snapshot

 

snapshot [-l | -a snapshot | -c snapshot | -d snapshot ] filename

list (-l)

# qemu-img snapshot -l centos6.3.qcow2

Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
3         1345047956                0 2012-08-16 00:25:56   00:00:00.000

 

apply (-a)

# qemu-img snapshot -a 1345047956 centos6.3.qcow2

 

create(-c)

# qemu-img snapshot -c 12345 centos6.3.qcow2

Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
3         1345047956                0 2012-08-16 00:25:56   00:00:00.000
4         12345                     0 2012-08-20 22:02:18   00:00:00.000

 

delete(-d)

# qemu-img snapshot -d 12345 centos6.3.qcow2

Snapshot list:
ID        TAG                 VM SIZE                DATE       VM CLOCK
3         1345047956                0 2012-08-16 00:25:56   00:00:00.000

 

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qemu-img

 

mv disk.qcow2 base_disk.qcow2
qemu-img create -c -b base_disk.qcow2 delta_disk.qcow2
ln -s delta_disk.qcow2 disk.qcow2

# formats "qcow2" and "qed"
rebase  [-p] [-u] -b backing_file [-F backing_fmt] filename

Safe mode (default)
# merged into filename before actually changing the backing file.
# expensive operation, comparable to converting an image.

Unsafe mode
#  without any checks on the file contents.
# fix an image whose backing file has already been moved/renamed.

# Commit the changes recorded in filename in its base image.
commit filename
 

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virtio-rng

paravirtualized device that is exposed as a hardware RNG device to the guest.

* Linux kernel contains the guest driver

-device virtio-rng-pci

* default backend is to use the host's /dev/random

-object rng-random,filename=/dev/hwrng,id=rng0 \
-device virtio-rng-pci,rng=rng0

cat /sys/devices/virtual/misc/hw_random/rng_available
virtio

cat /sys/devices/virtual/misc/hw_random/rng_current
virtio

cat /dev/hwrng

 

rngd -r /dev/hwrng