blog/Migrating_Xen_virtual_machines_using_LVM_to_KVM_using_disk_images.html

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
   2           "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
   3 <html xmlns="http://www.w3.org/1999/xhtml" dir="ltr">
   4   <head>
   5     <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
   6     <title>Petter Reinholdtsen: Migrating Xen virtual machines using LVM to KVM using disk images</title>
   7     <link rel="stylesheet" type="text/css" media="screen" href="http://people.skolelinux.org/pere/blog/style.css" />
   8     <link rel="stylesheet" type="text/css" media="screen" href="http://people.skolelinux.org/pere/blog/vim.css" />
   9
  10
  11   </head>
  12   <body>
  13     <div class="title">
  14  <h1>
  15      <a href="http://people.skolelinux.org/pere/blog/">Petter Reinholdtsen</a>
  16
  17  </h1>
  18
  19 </div>
  20
  21
  22     <div class="entry">
  23       <div class="title">Migrating Xen virtual machines using LVM to KVM using disk images</div>
  24       <div class="date">22nd November 2010</div>
  25       <div class="body"><p>Most of the computers in use by the
  26 <a href="http://www.skolelinux.org/">Debian Edu/Skolelinux project</a>
  27 are virtual machines.  And they have been Xen machines running on a
  28 fairly old IBM eserver xseries 345 machine, and we wanted to migrate
  29 them to KVM on a newer Dell PowerEdge 2950 host machine.  This was a
  30 bit harder that it could have been, because we set up the Xen virtual
  31 machines to get the virtual partitions from LVM, which as far as I
  32 know is not supported by KVM.  So to migrate, we had to convert
  33 several LVM logical volumes to partitions on a virtual disk file.</p>
  34
  35 <p>I found
  36 <a href="http://searchnetworking.techtarget.com.au/articles/35011-Six-steps-for-migrating-Xen-virtual-machines-to-KVM">a
  37 nice recipe</a> to do this, and wrote the following script to do the
  38 migration.  It uses qemu-img from the qemu package to make the disk
  39 image, parted to partition it, losetup and kpartx to present the disk
  40 image partions as devices, and dd to copy the data.  I NFS mounted the
  41 new servers storage area on the old server to do the migration.</p>
  42
  43 <pre>
  44 #!/bin/sh
  45
  46 # Based on
  47 # http://searchnetworking.techtarget.com.au/articles/35011-Six-steps-for-migrating-Xen-virtual-machines-to-KVM
  48
  49 set -e
  50 set -x
  51
  52 if [ -z "$1" ] ; then
  53     echo "Usage: $0 &lt;hostname&gt;"
  54     exit 1
  55 else
  56     host="$1"
  57 fi
  58
  59 if [ ! -e /dev/vg_data/$host-disk ] ; then
  60     echo "error: unable to find LVM volume for $host"
  61     exit 1
  62 fi
  63
  64 # Partitions need to be a bit bigger than the LVM LVs.  not sure why.
  65 disksize=$( lvs --units m | grep $host-disk | awk '{sum = sum + $4} END { print int(sum * 1.05) }')
  66 swapsize=$( lvs --units m | grep $host-swap | awk '{sum = sum + $4} END { print int(sum * 1.05) }')
  67 totalsize=$(( ( $disksize + $swapsize ) ))
  68
  69 img=$host.img
  70 #dd if=/dev/zero of=$img bs=1M count=$(( $disksize + $swapsize ))
  71 qemu-img create $img ${totalsize}MMaking room on the Debian Edu/Sqeeze DVD
  72
  73 parted $img mklabel msdos
  74 parted $img mkpart primary linux-swap 0 $disksize
  75 parted $img mkpart primary ext2 $disksize $totalsize
  76 parted $img set 1 boot on
  77
  78 modprobe dm-mod
  79 losetup /dev/loop0 $img
  80 kpartx -a /dev/loop0
  81
  82 dd if=/dev/vg_data/$host-disk of=/dev/mapper/loop0p1 bs=1M
  83 fsck.ext3 -f /dev/mapper/loop0p1 || true
  84 mkswap /dev/mapper/loop0p2
  85
  86 kpartx -d /dev/loop0
  87 losetup -d /dev/loop0
  88 </pre>
  89
  90 <p>The script is perhaps so simple that it is not copyrightable, but
  91 if it is, it is licenced using GPL v2 or later at your discretion.</p>
  92
  93 <p>After doing this, I booted a Debian CD in rescue mode in KVM with
  94 the new disk image attached, installed grub-pc and linux-image-686 and
  95 set up grub to boot from the disk image.  After this, the KVM machines
  96 seem to work just fine.</p>
  97 </div>
  98
  99       <div class="tags">Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.</div>
 100
 101
 102     </div>
 103
 104
 105
 106
 107     <div id="sidebar">
 108
 109
 110
 111 <h2>Archive</h2>
 112 <ul>
 113
 114 <li>2015
 115 <ul>
 116
 117 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/01/">January (7)</a></li>
 118
 119 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/02/">February (6)</a></li>
 120
 121 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/03/">March (1)</a></li>
 122
 123 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/04/">April (4)</a></li>
 124
 125 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/05/">May (3)</a></li>
 126
 127 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/06/">June (4)</a></li>
 128
 129 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/07/">July (5)</a></li>
 130
 131 </ul></li>
 132
 133 <li>2014
 134 <ul>
 135
 136 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/01/">January (2)</a></li>
 137
 138 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/02/">February (3)</a></li>
 139
 140 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/03/">March (8)</a></li>
 141
 142 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/04/">April (7)</a></li>
 143
 144 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/05/">May (1)</a></li>
 145
 146 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/06/">June (2)</a></li>
 147
 148 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/07/">July (2)</a></li>
 149
 150 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/08/">August (2)</a></li>
 151
 152 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/09/">September (5)</a></li>
 153
 154 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/10/">October (6)</a></li>
 155
 156 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/11/">November (3)</a></li>
 157
 158 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/12/">December (5)</a></li>
 159
 160 </ul></li>
 161
 162 <li>2013
 163 <ul>
 164
 165 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/01/">January (11)</a></li>
 166
 167 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/02/">February (9)</a></li>
 168
 169 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/03/">March (9)</a></li>
 170
 171 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/04/">April (6)</a></li>
 172
 173 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/05/">May (9)</a></li>
 174
 175 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/06/">June (10)</a></li>
 176
 177 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/07/">July (7)</a></li>
 178
 179 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/08/">August (3)</a></li>
 180
 181 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/09/">September (5)</a></li>
 182
 183 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/10/">October (7)</a></li>
 184
 185 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/11/">November (9)</a></li>
 186
 187 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/12/">December (3)</a></li>
 188
 189 </ul></li>
 190
 191 <li>2012
 192 <ul>
 193
 194 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/01/">January (7)</a></li>
 195
 196 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/02/">February (10)</a></li>
 197
 198 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/03/">March (17)</a></li>
 199
 200 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/04/">April (12)</a></li>
 201
 202 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/05/">May (12)</a></li>
 203
 204 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/06/">June (20)</a></li>
 205
 206 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/07/">July (17)</a></li>
 207
 208 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/08/">August (6)</a></li>
 209
 210 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/09/">September (9)</a></li>
 211
 212 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/10/">October (17)</a></li>
 213
 214 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/11/">November (10)</a></li>
 215
 216 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/12/">December (7)</a></li>
 217
 218 </ul></li>
 219
 220 <li>2011
 221 <ul>
 222
 223 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/01/">January (16)</a></li>
 224
 225 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/02/">February (6)</a></li>
 226
 227 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/03/">March (6)</a></li>
 228
 229 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/04/">April (7)</a></li>
 230
 231 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/05/">May (3)</a></li>
 232
 233 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/06/">June (2)</a></li>
 234
 235 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/07/">July (7)</a></li>
 236
 237 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/08/">August (6)</a></li>
 238
 239 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/09/">September (4)</a></li>
 240
 241 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/10/">October (2)</a></li>
 242
 243 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/11/">November (3)</a></li>
 244
 245 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/12/">December (1)</a></li>
 246
 247 </ul></li>
 248
 249 <li>2010
 250 <ul>
 251
 252 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
 253
 254 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
 255
 256 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
 257
 258 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
 259
 260 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/05/">May (9)</a></li>
 261
 262 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/06/">June (14)</a></li>
 263
 264 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/07/">July (12)</a></li>
 265
 266 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/08/">August (13)</a></li>
 267
 268 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/09/">September (7)</a></li>
 269
 270 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/10/">October (9)</a></li>
 271
 272 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/11/">November (13)</a></li>
 273
 274 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/12/">December (12)</a></li>
 275
 276 </ul></li>
 277
 278 <li>2009
 279 <ul>
 280
 281 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
 282
 283 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
 284
 285 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
 286
 287 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
 288
 289 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
 290
 291 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
 292
 293 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
 294
 295 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
 296
 297 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
 298
 299 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
 300
 301 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
 302
 303 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
 304
 305 </ul></li>
 306
 307 <li>2008
 308 <ul>
 309
 310 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
 311
 312 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
 313
 314 </ul></li>
 315
 316 </ul>
 317
 318
 319
 320 <h2>Tags</h2>
 321 <ul>
 322
 323  <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (13)</a></li>
 324
 325  <li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
 326
 327  <li><a href="http://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
 328
 329  <li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
 330
 331  <li><a href="http://people.skolelinux.org/pere/blog/tags/bitcoin">bitcoin (8)</a></li>
 332
 333  <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (15)</a></li>
 334
 335  <li><a href="http://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
 336
 337  <li><a href="http://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
 338
 339  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (111)</a></li>
 340
 341  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (153)</a></li>
 342
 343  <li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (10)</a></li>
 344
 345  <li><a href="http://people.skolelinux.org/pere/blog/tags/dld">dld (15)</a></li>
 346
 347  <li><a href="http://people.skolelinux.org/pere/blog/tags/docbook">docbook (13)</a></li>
 348
 349  <li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
 350
 351  <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (283)</a></li>
 352
 353  <li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
 354
 355  <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (12)</a></li>
 356
 357  <li><a href="http://people.skolelinux.org/pere/blog/tags/freeculture">freeculture (15)</a></li>
 358
 359  <li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
 360
 361  <li><a href="http://people.skolelinux.org/pere/blog/tags/frikanalen">frikanalen (16)</a></li>
 362
 363  <li><a href="http://people.skolelinux.org/pere/blog/tags/h264">h264 (20)</a></li>
 364
 365  <li><a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju (42)</a></li>
 366
 367  <li><a href="http://people.skolelinux.org/pere/blog/tags/isenkram">isenkram (10)</a></li>
 368
 369  <li><a href="http://people.skolelinux.org/pere/blog/tags/kart">kart (19)</a></li>
 370
 371  <li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
 372
 373  <li><a href="http://people.skolelinux.org/pere/blog/tags/lenker">lenker (8)</a></li>
 374
 375  <li><a href="http://people.skolelinux.org/pere/blog/tags/lsdvd">lsdvd (2)</a></li>
 376
 377  <li><a href="http://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (1)</a></li>
 378
 379  <li><a href="http://people.skolelinux.org/pere/blog/tags/mesh network">mesh network (8)</a></li>
 380
 381  <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (36)</a></li>
 382
 383  <li><a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk (264)</a></li>
 384
 385  <li><a href="http://people.skolelinux.org/pere/blog/tags/nuug">nuug (177)</a></li>
 386
 387  <li><a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn (19)</a></li>
 388
 389  <li><a href="http://people.skolelinux.org/pere/blog/tags/open311">open311 (2)</a></li>
 390
 391  <li><a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (53)</a></li>
 392
 393  <li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (86)</a></li>
 394
 395  <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (1)</a></li>
 396
 397  <li><a href="http://people.skolelinux.org/pere/blog/tags/reactos">reactos (1)</a></li>
 398
 399  <li><a href="http://people.skolelinux.org/pere/blog/tags/reprap">reprap (11)</a></li>
 400
 401  <li><a href="http://people.skolelinux.org/pere/blog/tags/rfid">rfid (3)</a></li>
 402
 403  <li><a href="http://people.skolelinux.org/pere/blog/tags/robot">robot (9)</a></li>
 404
 405  <li><a href="http://people.skolelinux.org/pere/blog/tags/rss">rss (1)</a></li>
 406
 407  <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (4)</a></li>
 408
 409  <li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
 410
 411  <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (41)</a></li>
 412
 413  <li><a href="http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (4)</a></li>
 414
 415  <li><a href="http://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (4)</a></li>
 416
 417  <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (48)</a></li>
 418
 419  <li><a href="http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (3)</a></li>
 420
 421  <li><a href="http://people.skolelinux.org/pere/blog/tags/stortinget">stortinget (9)</a></li>
 422
 423  <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (33)</a></li>
 424
 425  <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (2)</a></li>
 426
 427  <li><a href="http://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
 428
 429  <li><a href="http://people.skolelinux.org/pere/blog/tags/valg">valg (8)</a></li>
 430
 431  <li><a href="http://people.skolelinux.org/pere/blog/tags/video">video (54)</a></li>
 432
 433  <li><a href="http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (4)</a></li>
 434
 435  <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (37)</a></li>
 436
 437 </ul>
 438
 439
 440     </div>
 441     <p style="text-align: right">
 442  Created by <a href="http://steve.org.uk/Software/chronicle">Chronicle v4.6</a>
 443 </p>
 444
 445   </body>
 446 </html>