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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
|
<?xml version="1.0"?>
<html>
<body>
<h1 >Storage Management</h1>
<p>
This page describes the backends for the storage management capabilities in
libvirt.
</p>
<ul>
<li>
<a href="#StorageBackendDir">Directory backend</a>
</li>
<li>
<a href="#StorageBackendFS">Local filesystem backend</a>
</li>
<li>
<a href="#StorageBackendNetFS">Network filesystem backend</a>
</li>
<li>
<a href="#StorageBackendLogical">Logical backend</a>
</li>
<li>
<a href="#StorageBackendDisk">Disk backend</a>
</li>
<li>
<a href="#StorageBackendISCSI">iSCSI backend</a>
</li>
</ul>
<h2><a name="StorageBackendDir" id="StorageBackendDir">Directory pool</a></h2>
<p>
A pool with a type of <code>dir</code> provides the means to manage
files within a directory. The files can be fully allocated raw files,
sparsely allocated raw files, or one of the special disk formats
such as <code>qcow</code>,<code>qcow2</code>,<code>vmdk</code>,
<code>cow</code>, etc as supported by the <code>qemu-img</code>
program. If the directory does not exist at the time the pool is
defined, the <code>build</code> operation can be used to create it.
</p>
<h3>Example pool input definition</h3>
<pre>
<pool type="dir">
<name>virtimages</name>
<target>
<path>/var/lib/virt/images</path>
</target>
</pool>
</pre>
<h3>Valid pool format types</h3>
<p>
The directory pool does not use the pool format type element.
</p>
<h3>Valid volume format types</h3>
<p>
One of the following options:
</p>
<ul>
<li><code>raw</code>: a plain file</li>
<li><code>bochs</code>: Bochs disk image format</li>
<li><code>cloop</code>: compressed loopback disk image format</li>
<li><code>cow</code>: User Mode Linux disk image format</li>
<li><code>dmg</code>: Mac disk image format</li>
<li><code>iso</code>: CDROM disk image format</li>
<li><code>qcow</code>: QEMU v1 disk image format</li>
<li><code>qcow2</code>: QEMU v2 disk image format</li>
<li><code>vmdk</code>: VMWare disk image format</li>
<li><code>vpc</code>: VirtualPC disk image format</li>
</ul>
<p>
When listing existing volumes all these formats are supported
natively. When creating new volumes, only a subset may be
available. The <code>raw</code> type is guaranteed always
available. The <code>qcow2</code> type can be created if
either <code>qemu-img</code> or <code>qcow-create</code> tools
are present. The others are dependent on support of the
<code>qemu-img</code> tool.
</p>
<h2><a name="StorageBackendFS" id="StorageBackendFS">Filesystem pool</a></h2>
<p>
This is a variant of the directory pool. Instead of creating a
directory on an existing mounted filesystem though, it expects
a source block device to be named. This block device will be
mounted and files managed in the directory of its mount point.
It will default to allowing the kernel to automatically discover
the filesystem type, though it can be specified manually if
required.
</p>
<h3>Example pool input</h3>
<pre>
<pool type="fs">
<name>virtimages</name>
<source>
<device path="/dev/VolGroup00/VirtImages"/>
</source>
<target>
<path>/var/lib/virt/images</path>
</target>
</pool>
</pre>
<h3>Valid pool format types</h3>
<p>
The filesystem pool supports the following formats:
</p>
<ul>
<li><code>auto</code> - automatically determine format</li>
<li>
<code>ext2</code>
</li>
<li>
<code>ext3</code>
</li>
<li>
<code>ext4</code>
</li>
<li>
<code>ufs</code>
</li>
<li>
<code>iso9660</code>
</li>
<li>
<code>udf</code>
</li>
<li>
<code>gfs</code>
</li>
<li>
<code>gfs2</code>
</li>
<li>
<code>vfat</code>
</li>
<li>
<code>hfs+</code>
</li>
<li>
<code>xfs</code>
</li>
</ul>
<h3>Valid volume format types</h3>
<p>
The valid volume types are the same as for the <code>directory</code>
pool type.
</p>
<h2><a name="StorageBackendNetFS" id="StorageBackendNetFS">Network filesystem pool</a></h2>
<p>
This is a variant of the filesystem pool. Instead of requiring
a local block device as the source, it requires the name of a
host and path of an exported directory. It will mount this network
filesystem and manage files within the directory of its mount
point. It will default to using NFS as the protocol.
</p>
<h3>Example pool input</h3>
<pre>
<pool type="netfs">
<name>virtimages</name>
<source>
<host name="nfs.example.com"/>
<dir path="/var/lib/virt/images"/>
</source>
<target>
<path>/var/lib/virt/images</path>
</target>
</pool>
</pre>
<h3>Valid pool format types</h3>
<p>
The network filesystem pool supports the following formats:
</p>
<ul>
<li><code>auto</code> - automatically determine format</li>
<li>
<code>nfs</code>
</li>
</ul>
<h3>Valid volume format types</h3>
<p>
The valid volume types are the same as for the <code>directory</code>
pool type.
</p>
<h2><a name="StorageBackendLogical" id="StorageBackendLogical">Logical volume pools</a></h2>
<p>
This provides a pool based on an LVM volume group. For a
pre-defined LVM volume group, simply providing the group
name is sufficient, while to build a new group requires
providing a list of source devices to serve as physical
volumes. Volumes will be allocated by carving out chunks
of storage from the volume group.
</p>
<h3>Example pool input</h3>
<pre>
<pool type="logical">
<name>HostVG</name>
<source>
<device path="/dev/sda1"/>
<device path="/dev/sdb1"/>
<device path="/dev/sdc1"/>
</source>
<target>
<path>/dev/HostVG</path>
</target>
</pool>
</pre>
<h3>Valid pool format types</h3>
<p>
The logical volume pool does not use the pool format type element.
</p>
<h3>Valid volume format types</h3>
<p>
The logical volume pool does not use the volume format type element.
</p>
<h2><a name="StorageBackendDisk" id="StorageBackendDisk">Disk volume pools</a></h2>
<p>
This provides a pool based on a physical disk. Volumes are created
by adding partitions to the disk. Disk pools are have constraints
on the size and placement of volumes. The 'free extents'
information will detail the regions which are available for creating
new volumes. A volume cannot span across 2 different free extents.
</p>
<h3>Example pool input</h3>
<pre>
<pool type="disk">
<name>sda</name>
<source>
<device path='/dev/sda'/>
</source>
<target>
<path>/dev</path>
</target>
</pool>
</pre>
<h3>Valid pool format types</h3>
<p>
The disk volume pool accepts the following pool format types, representing
the common partition table types:
</p>
<ul>
<li>
<code>dos</code>
</li>
<li>
<code>dvh</code>
</li>
<li>
<code>gpt</code>
</li>
<li>
<code>mac</code>
</li>
<li>
<code>bsd</code>
</li>
<li>
<code>pc98</code>
</li>
<li>
<code>sun</code>
</li>
</ul>
<p>
The <code>dos</code> or <code>gpt</code> formats are recommended for
best portability - the latter is needed for disks larger than 2TB.
</p>
<h3>Valid volume format types</h3>
<p>
The disk volume pool accepts the following volume format types, representing
the common partition entry types:
</p>
<ul>
<li>
<code>none</code>
</li>
<li>
<code>linux</code>
</li>
<li>
<code>fat16</code>
</li>
<li>
<code>fat32</code>
</li>
<li>
<code>linux-swap</code>
</li>
<li>
<code>linux-lvm</code>
</li>
<li>
<code>linux-raid</code>
</li>
<li>
<code>extended</code>
</li>
</ul>
<h2><a name="StorageBackendISCSI" id="StorageBackendISCSI">iSCSI volume pools</a></h2>
<p>
This provides a pool based on an iSCSI target. Volumes must be
pre-allocated on the iSCSI server, and cannot be created via
the libvirt APIs. Since /dev/XXX names may change each time libvirt
logs into the iSCSI target, it is recommended to configure the pool
to use <code>/dev/disk/by-path</code> or <code>/dev/disk/by-id</code>
for the target path. These provide persistent stable naming for LUNs
</p>
<h3>Example pool input</h3>
<pre>
<pool type="iscsi">
<name>virtimages</name>
<source>
<host name="iscsi.example.com"/>
<device path="demo-target"/>
</source>
<target>
<path>/dev/disk/by-path</path>
</target>
</pool>
</pre>
<h3>Valid pool format types</h3>
<p>
The logical volume pool does not use the pool format type element.
</p>
<h3>Valid volume format types</h3>
<p>
The logical volume pool does not use the volume format type element.
</p>
</body>
</html>
|
