about summary refs log tree commit diff stats
path: root/tools/qemu.html
blob: ce1b66dd2eecbe4690a79289e8ad1b13f826121d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
<!DOCTYPE html>
<html dir="ltr" lang="en">
    <head>
        <meta charset='utf-8'>
        <title>Qemu</title>
    </head>
    <body>

        <a href="index.html">Tools Index</a>

        <h1>Qemu</h1>

        <h2 id="kern">1. Host System</h2>

        <p>Load modules, in this case kvm of intel cpu;</p>

        <pre>
        # modprobe -a kvm-intel tun virtio
        </pre>

        <p>Add users to kvm group;</p>

        <pre>
        # usermod -a -G kvm c9admin
        # usermod -a -G kvm username
        </pre>

        <h2 id="disk">2. Disk images</h2>

        <dl>
            <dt>img</dt>
            <dd>Raw disk image, allows dd to a physical device.</dd>
            <dt>raw</dt>
            <dd>Raw disk image, allows dd to a physical device.</dd>
            <dt>qcow2</dt>
            <dd>Qcow disk image file used by qemu.</dd>
        </dl>

        <p>Create hard disk image, there is different types,
        this describes how to create a qcow2 type;</p>

        <pre>
        $ qemu-img create -f qcow2 crux-img.qcow2 15G
        </pre>

        <p>You can mount disk image;</p>

        <pre>
        $ sudo modprobe nbd
        $ sudo qemu-nbd -c /dev/nbd0 /crux-img.qcow2
        </pre>

        <p>To disconnect image disk (ndb);</p>

        <pre>
        $ sudo qemu-nbd -d /dev/nbd0
        </pre>

        <p>Information about preparing
        <a href="../core/install.html#step2">partitions</a>
        and <a href="storage.html">storage</a> administration.
        You can use image as a normal disk, example how
        to use parted to create a gpt system table;</p>

        <pre>
        # parted /dev/nbd0
        (parted) mklabel gpt
        (parted) mkpart ext4 0% 100%
        (parted) set 1 boot on
        </pre>

        <pre>
        # kpartx -a -s -l -u /dev/nbd0
        </pre>

        <pre>
        # mkfs.ext4 /dev/mapper/nbd0p1
        </pre>

        <p>Mount partition;</p>

        <pre>
        # mount /dev/mapper/nbd0p1
        </pre>

        <h2 id="net">2. Network</h2>

        <p>Network configuration;</p>

        <dl>
            <dt>slirp</dt>
            <dd>Default virtual NAT'd network.</dd>
            <dt>tun/tap</dt>
            <dd>Good performance to create virtually any type of network
            topology.</dd>
            <dt>vde</dt>
            <dd>The VDE networking backend.</dd>
        </dl>


        <h3>2.1. Tap interfaces</h3>

        <pre>
        KERNEL=="tun", GROUP="kvm", MODE="0660", OPTIONS+="static_node=net/tun"
        </pre>

        <p>Automatic creation of tap interface with
        correct permissions set for user and group,
        you can set only user or group;</p>

        <pre>
        # tunctl -u username -g kvm -t tap0
        </pre>

        <p>Set permissions to existing tap interface;</p>

        <pre>
        # tunctl -u username -t tap0
        </pre>


        <p>Manual creation of tap interface;</p>

        <pre>
        # ip tuntap add name tap0 mode tap
        # chmod 0666 /dev/tap0
        # chown root:username /dev/tap0
        </pre>

        <pre>
        # ip addr add 10.0.2.1/24 dev tap0
        # ip link set dev tap0 up
        # ip link show
        </pre>

        <pre>
        # sysctl -w net.ipv4.ip_forward=1
        # iptables -t nat -A POSTROUTING -s 10.0.2.0/24 -o eth0 -j MASQUERADE
        </pre>

        <h2 id="guest">Guest System</h2>

        <p>Start qemu with 512 of ram, mydisk.img as disk and boot from iso</p>

        <pre>
        $ qemu-system-x86_64 \
        -enable-kvm \
        -m 512 \
        -boot d -cdrom image.iso \
        -hda mydisk.img
        </pre>

        <p>Start qemu with 1024 of ram, network configured using tap0
        interface device no host and boot from crux.qcow2;</p>

        <pre>
        $ qemu-system-x86_64 \
        -enable-kvm \
        -m 1024 \
        -hda c9/local/crux.qcow2 \
        -net nic,model=virtio -net tap,ifname=tap0,script=no,downscript=no
        </pre>

        <a href="index.html">Tools Index</a>
        <p>This is part of the c9 Manual.
        Copyright (C) 2016
        c9 team.
        See the file <a href="../fdl-1.3-standalone.html">Gnu Free Documentation License</a>
        for copying conditions.</p>
    </body>
</html>