blog/Fixing_an_hanging_debian_installer_for_Debian_Edu.html

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   6     <title>Petter Reinholdtsen: Fixing an hanging debian installer for Debian Edu</title>
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  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">Fixing an hanging debian installer for Debian Edu</div>
  24       <div class="date"> 3rd January 2012</div>
  25       <div class="body"><p>During christmas, I have been working getting the next version of
  26 <a href="http://www.skolelinux.org/">Debian Edu / Skolelinux</a> ready
  27 for release.  The initial problem I looked at was particularly
  28 interesting.</p>
  29
  30 <P>The installer would hang at the end when it was doing it
  31 post-installation configuration, and whatevery I did to try to find
  32 the cause and fix it always worked while I tested it, but never when I
  33 integrated it into the installer and ran the installation from
  34 scratch.  I would try to restart processes, close file descriptors,
  35 remove or create files, and the installer would always unblock and
  36 wrap up its tasks.</p>
  37
  38 <p>Eventually the cause was found.  The kernel was simply running out
  39 of entropy, causing the Kerberos setup to hang waiting for more.
  40 Pressing keys was adding entropy to the kernel, and thus all my tries
  41 to fix the problem worked not because what I was typing to fix it, but
  42 because I was typing.</P>
  43
  44 <p>The fix I implemented was to add a background process looking at
  45 the level of entropy in the kernel (by checking
  46 /proc/sys/kernel/random/entropy_avail), and if it was too small, the
  47 installer will flush the kernel file buffers and do 'find /' to
  48 generate some disk IO.  Disk IO generate entropy in the kernel, and is
  49 one of the few things that can be initated from within the system to
  50 generate entropy.</p>
  51
  52 <p>The fix is in
  53 <a href="http://wiki.debian.org/DebianEdu/Documentation/Squeeze/Installation">beta1
  54 of the Debian Edu/Squeeze</a> version, and we
  55 <a href="http://wiki.debian.org/DebianEdu">welcome more testers and
  56 developers</a>.  We plan to release beta2 this weekend.</p>
  57 </div>
  58
  59       <div class="tags">Tags: <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>
  60
  61
  62     </div>
  63
  64
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  67     <div id="sidebar">
  68
  69
  70
  71 <h2>Archive</h2>
  72 <ul>
  73
  74 <li>2017
  75 <ul>
  76
  77 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/01/">January (4)</a></li>
  78
  79 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/02/">February (3)</a></li>
  80
  81 <li><a href="http://people.skolelinux.org/pere/blog/archive/2017/03/">March (3)</a></li>
  82
  83 </ul></li>
  84
  85 <li>2016
  86 <ul>
  87
  88 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/01/">January (3)</a></li>
  89
  90 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/02/">February (2)</a></li>
  91
  92 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/03/">March (3)</a></li>
  93
  94 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/04/">April (8)</a></li>
  95
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  99
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 103
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 105
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 107
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 109
 110 <li><a href="http://people.skolelinux.org/pere/blog/archive/2016/12/">December (5)</a></li>
 111
 112 </ul></li>
 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
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 122
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 124
 125 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/05/">May (3)</a></li>
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 127 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/06/">June (4)</a></li>
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 129 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/07/">July (6)</a></li>
 130
 131 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/08/">August (2)</a></li>
 132
 133 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/09/">September (2)</a></li>
 134
 135 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/10/">October (9)</a></li>
 136
 137 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/11/">November (6)</a></li>
 138
 139 <li><a href="http://people.skolelinux.org/pere/blog/archive/2015/12/">December (3)</a></li>
 140
 141 </ul></li>
 142
 143 <li>2014
 144 <ul>
 145
 146 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/01/">January (2)</a></li>
 147
 148 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/02/">February (3)</a></li>
 149
 150 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/03/">March (8)</a></li>
 151
 152 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/04/">April (7)</a></li>
 153
 154 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/05/">May (1)</a></li>
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 156 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/06/">June (2)</a></li>
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 158 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/07/">July (2)</a></li>
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 160 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/08/">August (2)</a></li>
 161
 162 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/09/">September (5)</a></li>
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 164 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/10/">October (6)</a></li>
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 166 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/11/">November (3)</a></li>
 167
 168 <li><a href="http://people.skolelinux.org/pere/blog/archive/2014/12/">December (5)</a></li>
 169
 170 </ul></li>
 171
 172 <li>2013
 173 <ul>
 174
 175 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/01/">January (11)</a></li>
 176
 177 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/02/">February (9)</a></li>
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 179 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/03/">March (9)</a></li>
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 181 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/04/">April (6)</a></li>
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 183 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/05/">May (9)</a></li>
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 185 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/06/">June (10)</a></li>
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 187 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/07/">July (7)</a></li>
 188
 189 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/08/">August (3)</a></li>
 190
 191 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/09/">September (5)</a></li>
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 193 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/10/">October (7)</a></li>
 194
 195 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/11/">November (9)</a></li>
 196
 197 <li><a href="http://people.skolelinux.org/pere/blog/archive/2013/12/">December (3)</a></li>
 198
 199 </ul></li>
 200
 201 <li>2012
 202 <ul>
 203
 204 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/01/">January (7)</a></li>
 205
 206 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/02/">February (10)</a></li>
 207
 208 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/03/">March (17)</a></li>
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 212 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/05/">May (12)</a></li>
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 214 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/06/">June (20)</a></li>
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 216 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/07/">July (17)</a></li>
 217
 218 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/08/">August (6)</a></li>
 219
 220 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/09/">September (9)</a></li>
 221
 222 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/10/">October (17)</a></li>
 223
 224 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/11/">November (10)</a></li>
 225
 226 <li><a href="http://people.skolelinux.org/pere/blog/archive/2012/12/">December (7)</a></li>
 227
 228 </ul></li>
 229
 230 <li>2011
 231 <ul>
 232
 233 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/01/">January (16)</a></li>
 234
 235 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/02/">February (6)</a></li>
 236
 237 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/03/">March (6)</a></li>
 238
 239 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/04/">April (7)</a></li>
 240
 241 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/05/">May (3)</a></li>
 242
 243 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/06/">June (2)</a></li>
 244
 245 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/07/">July (7)</a></li>
 246
 247 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/08/">August (6)</a></li>
 248
 249 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/09/">September (4)</a></li>
 250
 251 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/10/">October (2)</a></li>
 252
 253 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/11/">November (3)</a></li>
 254
 255 <li><a href="http://people.skolelinux.org/pere/blog/archive/2011/12/">December (1)</a></li>
 256
 257 </ul></li>
 258
 259 <li>2010
 260 <ul>
 261
 262 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/01/">January (2)</a></li>
 263
 264 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/02/">February (1)</a></li>
 265
 266 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/03/">March (3)</a></li>
 267
 268 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/04/">April (3)</a></li>
 269
 270 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/05/">May (9)</a></li>
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 272 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/06/">June (14)</a></li>
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 274 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/07/">July (12)</a></li>
 275
 276 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/08/">August (13)</a></li>
 277
 278 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/09/">September (7)</a></li>
 279
 280 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/10/">October (9)</a></li>
 281
 282 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/11/">November (13)</a></li>
 283
 284 <li><a href="http://people.skolelinux.org/pere/blog/archive/2010/12/">December (12)</a></li>
 285
 286 </ul></li>
 287
 288 <li>2009
 289 <ul>
 290
 291 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/01/">January (8)</a></li>
 292
 293 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/02/">February (8)</a></li>
 294
 295 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/03/">March (12)</a></li>
 296
 297 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/04/">April (10)</a></li>
 298
 299 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/05/">May (9)</a></li>
 300
 301 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/06/">June (3)</a></li>
 302
 303 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/07/">July (4)</a></li>
 304
 305 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/08/">August (3)</a></li>
 306
 307 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/09/">September (1)</a></li>
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 309 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/10/">October (2)</a></li>
 310
 311 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/11/">November (3)</a></li>
 312
 313 <li><a href="http://people.skolelinux.org/pere/blog/archive/2009/12/">December (3)</a></li>
 314
 315 </ul></li>
 316
 317 <li>2008
 318 <ul>
 319
 320 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/11/">November (5)</a></li>
 321
 322 <li><a href="http://people.skolelinux.org/pere/blog/archive/2008/12/">December (7)</a></li>
 323
 324 </ul></li>
 325
 326 </ul>
 327
 328
 329
 330 <h2>Tags</h2>
 331 <ul>
 332
 333  <li><a href="http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (13)</a></li>
 334
 335  <li><a href="http://people.skolelinux.org/pere/blog/tags/amiga">amiga (1)</a></li>
 336
 337  <li><a href="http://people.skolelinux.org/pere/blog/tags/aros">aros (1)</a></li>
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 339  <li><a href="http://people.skolelinux.org/pere/blog/tags/bankid">bankid (4)</a></li>
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 343  <li><a href="http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (16)</a></li>
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 345  <li><a href="http://people.skolelinux.org/pere/blog/tags/bsa">bsa (2)</a></li>
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 347  <li><a href="http://people.skolelinux.org/pere/blog/tags/chrpath">chrpath (2)</a></li>
 348
 349  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian">debian (147)</a></li>
 350
 351  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (158)</a></li>
 352
 353  <li><a href="http://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook (3)</a></li>
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 355  <li><a href="http://people.skolelinux.org/pere/blog/tags/digistan">digistan (10)</a></li>
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 363  <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (344)</a></li>
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 365  <li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
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 367  <li><a href="http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (12)</a></li>
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 371  <li><a href="http://people.skolelinux.org/pere/blog/tags/freedombox">freedombox (9)</a></li>
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 377  <li><a href="http://people.skolelinux.org/pere/blog/tags/intervju">intervju (42)</a></li>
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 383  <li><a href="http://people.skolelinux.org/pere/blog/tags/ldap">ldap (9)</a></li>
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 393  <li><a href="http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (39)</a></li>
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 395  <li><a href="http://people.skolelinux.org/pere/blog/tags/nice free software">nice free software (9)</a></li>
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 415  <li><a href="http://people.skolelinux.org/pere/blog/tags/rfid">rfid (3)</a></li>
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 417  <li><a href="http://people.skolelinux.org/pere/blog/tags/robot">robot (10)</a></li>
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 421  <li><a href="http://people.skolelinux.org/pere/blog/tags/ruter">ruter (5)</a></li>
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 423  <li><a href="http://people.skolelinux.org/pere/blog/tags/scraperwiki">scraperwiki (2)</a></li>
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 425  <li><a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (52)</a></li>
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 429  <li><a href="http://people.skolelinux.org/pere/blog/tags/skepsis">skepsis (5)</a></li>
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 431  <li><a href="http://people.skolelinux.org/pere/blog/tags/standard">standard (51)</a></li>
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 437  <li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (48)</a></li>
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 439  <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (2)</a></li>
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 441  <li><a href="http://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
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 449  <li><a href="http://people.skolelinux.org/pere/blog/tags/web">web (40)</a></li>
 450
 451 </ul>
 452
 453
 454     </div>
 455     <p style="text-align: right">
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