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  12   <h1>
  13        <a href="../../">Petter Reinholdtsen</a>
  14
  15   </h1>
  16
  17  </div>
  18
  19  <p>Entries tagged "english".</p>
  20
  21
  22
  23
  24 <div class="entry">
  25  <div class="title">
  26  <a href="../../The_sorry_state_of_multimedia_browser_plugins_in_Debian.html">The sorry state of multimedia browser plugins in Debian</a>
  27  </div>
  28  <div class="date">
  29   2008-11-25 00:10
  30  </div>
  31
  32  <div class="body">
  33
  34 <p>Recently I have spent some time evaluating the multimedia browser
  35 plugins available in Debian Lenny, to see which one we should use by
  36 default in Debian Edu.  We need an embedded video playing plugin with
  37 control buttons to pause or stop the video, and capable of streaming
  38 all the multimedia content available on the web.  The test results and
  39 notes are available on
  40 <a href="http://wiki.debian.org/DebianEdu/BrowserMultimedia">the
  41 Debian wiki</a>.  I was surprised how few of the plugins are able to
  42 fill this need.  My personal video player favorite, VLC, has a really
  43 bad plugin which fail on a lot of the test pages.  A lot of the MIME
  44 types I would expect to work with any free software player (like
  45 video/ogg), just do not work.  And simple formats like the
  46 audio/x-mplegurl format (m3u playlists), just isn't supported by the
  47 totem and vlc plugins.  I hope the situation will improve soon.  No
  48 wonder sites use the proprietary Adobe flash to play video.</p>
  49
  50 <p>For Lenny, we seem to end up with the mplayer plugin.  It seem to
  51 be the only one fitting our needs. :/</p>
  52
  53  </div>
  54  <div class="tags">
  55
  56
  57
  58   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/debian edu">debian edu</a>, <a href="../../tags/english">english</a>, <a href="../../tags/multimedia">multimedia</a>, <a href="../../tags/web">web</a>.
  59
  60  </div>
  61 </div>
  62 <div class="padding"></div>
  63
  64 <div class="entry">
  65  <div class="title">
  66  <a href="../../Devcamp_brought_us_closer_to_the_Lenny_based_Debian_Edu_release.html">Devcamp brought us closer to the Lenny based Debian Edu release</a>
  67  </div>
  68  <div class="date">
  69   2008-12-07 12:00
  70  </div>
  71
  72  <div class="body">
  73
  74 <p>This weekend we had a small developer gathering for Debian Edu in
  75 Oslo.  Most of Saturday was used for the general assemly for the
  76 member organization, but the rest of the weekend I used to tune the
  77 LTSP installation.  LTSP now work out of the box on the 10-network.
  78 Acer Aspire One proved to be a very nice thin client, with both
  79 screen, mouse and keybard in a small box.  Was working on getting the
  80 diskless workstation setup configured out of the box, but did not
  81 finish it before the weekend was up.</p>
  82
  83 <p>Did not find time to look at the 4 VGA cards in one box we got from
  84 the Brazilian group, so that will have to wait for the next
  85 development gathering.  Would love to have the Debian Edu installer
  86 automatically detect and configure a multiseat setup when it find one
  87 of these cards.</p>
  88
  89  </div>
  90  <div class="tags">
  91
  92
  93
  94   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/debian edu">debian edu</a>, <a href="../../tags/english">english</a>, <a href="../../tags/ltsp">ltsp</a>.
  95
  96  </div>
  97 </div>
  98 <div class="padding"></div>
  99
 100 <div class="entry">
 101  <div class="title">
 102  <a href="../../Software_video_mixer_on_a_USB_stick.html">Software video mixer on a USB stick</a>
 103  </div>
 104  <div class="date">
 105   2008-12-28 15:40
 106  </div>
 107
 108  <div class="body">
 109
 110 <p>The <a href="http://www.nuug.no/">Norwegian Unix User Group</a> is
 111 recording our montly presentation on video, and recently we have
 112 worked on improving the quality of the recordings by mixing the slides
 113 directly with the video stream.  For this, we use the
 114 <a href="http://dvswitch.alioth.debian.org/">dvswitch</a> package from
 115 the Debian video team.  As this require quite one computer per video
 116 source, and NUUG do not have enough laptops available, we need to
 117 borrow laptops.  And to avoid having to install extra software on
 118 these borrwed laptops, I have wrapped up all the programs needed on a
 119 bootable USB stick.  The software required is dvswitch with assosiated
 120 source, sink and mixer applications and
 121 <a href="http://www.kinodv.org/">dvgrab</a>.  To allow this setup to
 122 work without any configuration, I've patched dvswitch to use
 123 <a href="http://www.avahi.org/">avahi</a> to connect the various parts
 124 together.  And to allow us to use laptops without firewire plugs, I
 125 upgraded dvgrab to the one from Debian/unstable to get one that work
 126 with USB sources.  We have not yet tested this setup in a production
 127 setup, but I hope it will work properly, and allow us to set up a
 128 video mixer in a very short time frame.  We will need it for
 129 <a href="http://www.goopen.no/">Go Open 2009</a>.</p>
 130
 131 <p><a href="http://www.nuug.no/pub/video/bin/usbstick-dvswitch.img.gz">The
 132 USB image</a> is for a 1 GB memory stick, but can be used on any
 133 larger stick as well.</p>
 134
 135  </div>
 136  <div class="tags">
 137
 138
 139
 140   Tags: <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>, <a href="../../tags/video">video</a>.
 141
 142  </div>
 143 </div>
 144 <div class="padding"></div>
 145
 146 <div class="entry">
 147  <div class="title">
 148  <a href="../../When_web_browser_developers_make_a_video_player___.html">When web browser developers make a video player...</a>
 149  </div>
 150  <div class="date">
 151   2009-01-17 18:50
 152  </div>
 153
 154  <div class="body">
 155
 156 <p>As part of the work we do in <a href="http://www.nuug.no">NUUG</a>
 157 to publish video recordings of our monthly presentations, we provide a
 158 page with embedded video for easy access to the recording.  Putting a
 159 good set of HTML tags together to get working embedded video in all
 160 browsers and across all operating systems is not easy.  I hope this
 161 will become easier when the &lt;video&gt; tag is implemented in all
 162 browsers, but I am not sure.  We provide the recordings in several
 163 formats, MPEG1, Ogg Theora, H.264 and Quicktime, and want the
 164 browser/media plugin to pick one it support and use it to play the
 165 recording, using whatever embed mechanism the browser understand.
 166 There is at least four different tags to use for this, the new HTML5
 167 &lt;video&gt; tag, the &lt;object&gt; tag, the &lt;embed&gt; tag and
 168 the &lt;applet&gt; tag.  All of these take a lot of options, and
 169 finding the best options is a major challenge.</p>
 170
 171 <p>I just tested the experimental Opera browser available from <a
 172 href="http://labs.opera.com">labs.opera.com</a>, to see how it handled
 173 a &lt;video&gt; tag with a few video sources and no extra attributes.
 174 I was not very impressed.  The browser start by fetching a picture
 175 from the video stream.  Not sure if it is the first frame, but it is
 176 definitely very early in the recording.  So far, so good. Next,
 177 instead of streaming the 76 MiB video file, it start to download all
 178 of it, but do not start to play the video.  This mean I have to wait
 179 for several minutes for the downloading to finish.  When the download
 180 is done, the playing of the video do not start!  Waiting for the
 181 download, but I do not get to see the video?  Some testing later, I
 182 discover that I have to add the controls="true" attribute to be able
 183 to get a play button to pres to start the video.  Adding
 184 autoplay="true" did not help.  I sure hope this is a misfeature of the
 185 test version of Opera, and that future implementations of the
 186 &lt;video&gt; tag will stream recordings by default, or at least start
 187 playing when the download is done.</p>
 188
 189 <p>The test page I used (since changed to add more attributes) is
 190 <a href="http://www.nuug.no/aktiviteter/20090113-foredrag-om-foredrag/">available
 191 from the nuug site</a>.  Will have to test it with the new Firefox
 192 too.</p>
 193
 194 <p>In the test process, I discovered a missing feature.  I was unable
 195 to find a way to get the URL of the playing video out of Opera, so I
 196 am not quite sure it picked the Ogg Theora version of the video.  I
 197 sure hope it was using the announced Ogg Theora support. :)</p>
 198
 199  </div>
 200  <div class="tags">
 201
 202
 203
 204   Tags: <a href="../../tags/english">english</a>, <a href="../../tags/multimedia">multimedia</a>, <a href="../../tags/nuug">nuug</a>, <a href="../../tags/video">video</a>, <a href="../../tags/web">web</a>.
 205
 206  </div>
 207 </div>
 208 <div class="padding"></div>
 209
 210 <div class="entry">
 211  <div class="title">
 212  <a href="../../Using_bar_codes_at_a_computing_center.html">Using bar codes at a computing center</a>
 213  </div>
 214  <div class="date">
 215   2009-02-20 08:50
 216  </div>
 217
 218  <div class="body">
 219
 220 <p>At work with the University of Oslo, we have several hundred computers
 221 in our computing center.  This give us a challenge in tracking the
 222 location and cabling of the computers, when they are added, moved and
 223 removed.  Some times the location register is not updated when a
 224 computer is inserted or moved and we then have to search the room for
 225 the "missing" computer.</p>
 226
 227 <p>In the last issue of Linux Journal, I came across a project
 228 <a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
 229 code blocks as defined in the
 230 <a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
 231 Standard</a>.  This is bar codes that can be read with a normal
 232 digital camera, for example that on a cell phone, and several such bar
 233 codes can be read by libdmtx from one picture.  The bar code standard
 234 allow up to 2 KiB to be written in the tag.  There is another project
 235 with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
 236 writer written in postscript</a> capable of creating such bar codes,
 237 but this was the first time I found a tool to read these bar
 238 codes.</p>
 239
 240 <p>It occurred to me that this could be used to tag and track the
 241 machines in our computing center.  If both racks and computers are
 242 tagged this way, we can use a picture of the rack and all its
 243 computers to detect the rack location of any computer in that rack.
 244 If we do this regularly for the entire room, we will find all
 245 locations, and can detect movements and removals.</p>
 246
 247 <p>I decided to test if this would work in practice, and picked a
 248 random rack and tagged all the machines with their names.  Next, I
 249 took pictures with my digital camera, and gave the dmtxread program
 250 these JPEG pictures to see how many tags it could read.  This worked
 251 fairly well.  If the pictures was well focused and not taken from the
 252 side, all tags in the image could be read.  Because of limited space
 253 between the racks, I was unable to get a good picture of the entire
 254 rack, but could without problem read all tags from a picture covering
 255 about half the rack.  I had to limit the search time used by dmtxread
 256 to 60000 ms to make sure it terminated in a reasonable time frame.</p>
 257
 258 <p>My conclusion is that this could work, and we should probably look
 259 at adjusting our computer tagging procedures to use bar codes for
 260 easier automatic tracking of computers.</p>
 261
 262  </div>
 263  <div class="tags">
 264
 265
 266
 267   Tags: <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 268
 269  </div>
 270 </div>
 271 <div class="padding"></div>
 272
 273 <div class="entry">
 274  <div class="title">
 275  <a href="../../Checking_server_hardware_support_status_for_Dell__HP_and_IBM_servers.html">Checking server hardware support status for Dell, HP and IBM servers</a>
 276  </div>
 277  <div class="date">
 278   2009-02-28 23:50
 279  </div>
 280
 281  <div class="body">
 282
 283 <p>At work, we have a few hundred Linux servers, and with that amount
 284 of hardware it is important to keep track of when the hardware support
 285 contract expire for each server.  We have a machine (and service)
 286 register, which until recently did not contain much useful besides the
 287 machine room location and contact information for the system owner for
 288 each machine.  To make it easier for us to track support contract
 289 status, I've recently spent time on extending the machine register to
 290 include information about when the support contract expire, and to tag
 291 machines with expired contracts to make it easy to get a list of such
 292 machines.  I extended a perl script already being used to import
 293 information about machines into the register, to also do some screen
 294 scraping off the sites of Dell, HP and IBM (our majority of machines
 295 are from these vendors), and automatically check the support status
 296 for the relevant machines.  This make the support status information
 297 easily available and I hope it will make it easier for the computer
 298 owner to know when to get new hardware or renew the support contract.
 299 The result of this work documented that 27% of the machines in the
 300 registry is without a support contract, and made it very easy to find
 301 them.  27% might seem like a lot, but I see it more as the case of us
 302 using machines a bit longer than the 3 years a normal support contract
 303 last, to have test machines and a platform for less important
 304 services.  After all, the machines without a contract are working fine
 305 at the moment and the lack of contract is only a problem if any of
 306 them break down.  When that happen, we can either fix it using spare
 307 parts from other machines or move the service to another old
 308 machine.</p>
 309
 310 <p>I believe the code for screen scraping the Dell site was originally
 311 written by Trond Hasle Amundsen, and later adjusted by me and Morten
 312 Werner Forsbring.  The HP scraping was written by me after reading a
 313 nice article in ;login: about how to use WWW::Mechanize, and the IBM
 314 scraping was written by me based on the Dell code.  I know the HTML
 315 parsing could be done using nice libraries, but did not want to
 316 introduce more dependencies.  This is the current incarnation:</p>
 317
 318 <pre>
 319 use LWP::Simple;
 320 use POSIX;
 321 use WWW::Mechanize;
 322 use Date::Parse;
 323 [...]
 324 sub get_support_info {
 325     my ($machine, $model, $serial, $productnumber) = @_;
 326     my $str;
 327
 328     if ( $model =~ m/^Dell / ) {
 329         # fetch website from Dell support
 330         my $url = "http://support.euro.dell.com/support/topics/topic.aspx/emea/shared/support/my_systems_info/no/details?c=no&amp;cs=nodhs1&amp;l=no&amp;s=dhs&amp;ServiceTag=$serial";
 331         my $webpage = get($url);
 332         return undef unless ($webpage);
 333
 334         my $daysleft = -1;
 335         my @lines = split(/\n/, $webpage);
 336         foreach my $line (@lines) {
 337             next unless ($line =~ m/Beskrivelse/);
 338             $line =~ s/&lt;[^>]+?>/;/gm;
 339             $line =~ s/^.+?;(Beskrivelse;)/$1/;
 340
 341             my @f = split(/\;/, $line);
 342             @f = @f[13 .. $#f];
 343             my $lastend = "";
 344             while ($f[3] eq "DELL") {
 345                 my ($type, $startstr, $endstr, $days) = @f[0, 5, 7, 10];
 346
 347                 my $start = POSIX::strftime("%Y-%m-%d",
 348                                             localtime(str2time($startstr)));
 349                 my $end = POSIX::strftime("%Y-%m-%d",
 350                                           localtime(str2time($endstr)));
 351                 $str .= "$type $start -> $end ";
 352                 @f = @f[14 .. $#f];
 353                 $lastend = $end if ($end gt $lastend);
 354             }
 355             my $today = POSIX::strftime("%Y-%m-%d", localtime(time));
 356             tag_machine_unsupported($machine)
 357                 if ($lastend lt $today);
 358         }
 359     } elsif ( $model =~ m/^HP / ) {
 360         my $mech = WWW::Mechanize->new();
 361         my $url =
 362             'http://www1.itrc.hp.com/service/ewarranty/warrantyInput.do';
 363         $mech->get($url);
 364         my $fields = {
 365             'BODServiceID' => 'NA',
 366             'RegisteredPurchaseDate' => '',
 367             'country' => 'NO',
 368             'productNumber' => $productnumber,
 369             'serialNumber1' => $serial,
 370         };
 371         $mech->submit_form( form_number => 2,
 372                             fields      => $fields );
 373         # Next step is screen scraping
 374         my $content = $mech->content();
 375
 376         $content =~ s/&lt;[^>]+?>/;/gm;
 377         $content =~ s/\s+/ /gm;
 378         $content =~ s/;\s*;/;;/gm;
 379         $content =~ s/;[\s;]+/;/gm;
 380
 381         my $today = POSIX::strftime("%Y-%m-%d", localtime(time));
 382
 383         while ($content =~ m/;Warranty Type;/) {
 384             my ($type, $status, $startstr, $stopstr) = $content =~
 385                 m/;Warranty Type;([^;]+);.+?;Status;(\w+);Start Date;([^;]+);End Date;([^;]+);/;
 386             $content =~ s/^.+?;Warranty Type;//;
 387             my $start = POSIX::strftime("%Y-%m-%d",
 388                                         localtime(str2time($startstr)));
 389             my $end = POSIX::strftime("%Y-%m-%d",
 390                                       localtime(str2time($stopstr)));
 391
 392             $str .= "$type ($status) $start -> $end ";
 393
 394             tag_machine_unsupported($machine)
 395                 if ($end lt $today);
 396         }
 397     } elsif ( $model =~ m/^IBM / ) {
 398         # This code ignore extended support contracts.
 399         my ($producttype) = $model =~ m/.*-\[(.{4}).+\]-/;
 400         if ($producttype &amp;&amp; $serial) {
 401             my $content =
 402                 get("http://www-947.ibm.com/systems/support/supportsite.wss/warranty?action=warranty&amp;brandind=5000008&amp;Submit=Submit&amp;type=$producttype&amp;serial=$serial");
 403             if ($content) {
 404                 $content =~ s/&lt;[^>]+?>/;/gm;
 405                 $content =~ s/\s+/ /gm;
 406                 $content =~ s/;\s*;/;;/gm;
 407                 $content =~ s/;[\s;]+/;/gm;
 408
 409                 $content =~ s/^.+?;Warranty status;//;
 410                 my ($status, $end) = $content =~ m/;Warranty status;([^;]+)\s*;Expiration date;(\S+) ;/;
 411
 412                 $str .= "($status) -> $end ";
 413
 414                 my $today = POSIX::strftime("%Y-%m-%d", localtime(time));
 415                 tag_machine_unsupported($machine)
 416                     if ($end lt $today);
 417             }
 418         }
 419     }
 420     return $str;
 421 }
 422 </pre>
 423
 424 <p>Here are some examples on how to use the function, using fake
 425 serial numbers.  The information passed in as arguments are fetched
 426 from dmidecode.</p>
 427
 428 <pre>
 429 print get_support_info("hp.host", "HP ProLiant BL460c G1", "1234567890"
 430                        "447707-B21");
 431 print get_support_info("dell.host", "Dell Inc. PowerEdge 2950", "1234567");
 432 print get_support_info("ibm.host", "IBM eserver xSeries 345 -[867061X]-",
 433                        "1234567");
 434 </pre>
 435
 436 <p>I would recommend this approach for tracking support contracts for
 437 everyone with more than a few computers to administer. :)</p>
 438
 439 <p>Update 2009-03-06: The IBM page do not include extended support
 440 contracts, so it is useless in that case.  The original Dell code do
 441 not handle extended support contracts either, but has been updated to
 442 do so.</p>
 443
 444  </div>
 445  <div class="tags">
 446
 447
 448
 449   Tags: <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 450
 451  </div>
 452 </div>
 453 <div class="padding"></div>
 454
 455 <div class="entry">
 456  <div class="title">
 457  <a href="../../Time_for_new__LDAP_schemas_replacing_RFC_2307_.html">Time for new  LDAP schemas replacing RFC 2307?</a>
 458  </div>
 459  <div class="date">
 460   2009-03-29 20:30
 461  </div>
 462
 463  <div class="body">
 464
 465 <p>The state of standardized LDAP schemas on Linux is far from
 466 optimal.  There is RFC 2307 documenting one way to store NIS maps in
 467 LDAP, and a modified version of this normally called RFC 2307bis, with
 468 some modifications to be compatible with Active Directory.  The RFC
 469 specification handle the content of a lot of system databases, but do
 470 not handle DNS zones and DHCP configuration.</p>
 471
 472 <p>In <a href="http://www.skolelinux.org/">Debian Edu/Skolelinux</a>,
 473 we would like to store information about users, SMB clients/hosts,
 474 filegroups, netgroups (users and hosts), DHCP and DNS configuration,
 475 and LTSP configuration in LDAP.  These objects have a lot in common,
 476 but with the current LDAP schemas it is not possible to have one
 477 object per entity.  For example, one need to have at least three LDAP
 478 objects for a given computer, one with the SMB related stuff, one with
 479 DNS information and another with DHCP information.  The schemas
 480 provided for DNS and DHCP are impossible to combine into one LDAP
 481 object.  In addition, it is impossible to implement quick queries for
 482 netgroup membership, because of the way NIS triples are implemented.
 483 It just do not scale.  I believe it is time for a few RFC
 484 specifications to cleam up this mess.</p>
 485
 486 <p>I would like to have one LDAP object representing each computer in
 487 the network, and this object can then keep the SMB (ie host key), DHCP
 488 (mac address/name) and DNS (name/IP address) settings in one place.
 489 It need to be efficently stored to make sure it scale well.</p>
 490
 491 <p>I would also like to have a quick way to map from a user or
 492 computer and to the net group this user or computer is a member.</p>
 493
 494 <p>Active Directory have done a better job than unix heads like myself
 495 in this regard, and the unix side need to catch up.  Time to start a
 496 new IETF work group?</p>
 497
 498  </div>
 499  <div class="tags">
 500
 501
 502
 503   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/debian edu">debian edu</a>, <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 504
 505  </div>
 506 </div>
 507 <div class="padding"></div>
 508
 509 <div class="entry">
 510  <div class="title">
 511  <a href="../../Returning_from_Skolelinux_developer_gathering.html">Returning from Skolelinux developer gathering</a>
 512  </div>
 513  <div class="date">
 514   2009-03-29 21:00
 515  </div>
 516
 517  <div class="body">
 518
 519 <p>I'm sitting on the train going home from this weekends Debian
 520 Edu/Skolelinux development gathering.  I got a bit done tuning the
 521 desktop, and looked into the dynamic service location protocol
 522 implementation avahi.  It look like it could be useful for us.  Almost
 523 30 people participated, and I believe it was a great environment to
 524 get to know the Skolelinux system.  Walter Bender, involved in the
 525 development of the Sugar educational platform, presented his stuff and
 526 also helped me improve my OLPC installation.  He also showed me that
 527 his Turtle Art application can be used in standalone mode, and we
 528 agreed that I would help getting it packaged for Debian.  As a
 529 standalone application it would be great for Debian Edu.  We also
 530 tried to get the video conferencing working with two OLPCs, but that
 531 proved to be too hard for us.  The application seem to need more work
 532 before it is ready for me.  I look forward to getting home and relax
 533 now. :)</p>
 534
 535  </div>
 536  <div class="tags">
 537
 538
 539
 540   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/debian edu">debian edu</a>, <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 541
 542  </div>
 543 </div>
 544 <div class="padding"></div>
 545
 546 <div class="entry">
 547  <div class="title">
 548  <a href="../../Standardize_on_protocols_and_formats__not_vendors_and_applications.html">Standardize on protocols and formats, not vendors and applications</a>
 549  </div>
 550  <div class="date">
 551   2009-03-30 11:50
 552  </div>
 553
 554  <div class="body">
 555
 556 <p>Where I work at the University of Oslo, one decision stand out as a
 557 very good one to form a long lived computer infrastructure.  It is the
 558 simple one, lost by many in todays computer industry: Standardize on
 559 open network protocols and open exchange/storage formats, not applications.
 560 Applications come and go, while protocols and files tend to stay, and
 561 thus one want to make it easy to change application and vendor, while
 562 avoiding conversion costs and locking users to a specific platform or
 563 application.</p>
 564
 565 <p>This approach make it possible to replace the client applications
 566 independently of the server applications.  One can even allow users to
 567 use several different applications as long as they handle the selected
 568 protocol and format.  In the normal case, only one client application
 569 is recommended and users only get help if they choose to use this
 570 application, but those that want to deviate from the easy path are not
 571 blocked from doing so.</p>
 572
 573 <p>It also allow us to replace the server side without forcing the
 574 users to replace their applications, and thus allow us to select the
 575 best server implementation at any moment, when scale and resouce
 576 requirements change.</p>
 577
 578 <p>I strongly recommend standardizing - on open network protocols and
 579 open formats, but I would never recommend standardizing on a single
 580 application that do not use open network protocol or open formats.</p>
 581
 582  </div>
 583  <div class="tags">
 584
 585
 586
 587   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>, <a href="../../tags/standard">standard</a>.
 588
 589  </div>
 590 </div>
 591 <div class="padding"></div>
 592
 593 <div class="entry">
 594  <div class="title">
 595  <a href="../../Recording_video_from_cron_using_VLC.html">Recording video from cron using VLC</a>
 596  </div>
 597  <div class="date">
 598   2009-04-05 10:00
 599  </div>
 600
 601  <div class="body">
 602
 603 <p>One think I have wanted to figure out for a along time is how to
 604 run vlc from cron to do recording of video streams on the net.  The
 605 task is trivial with mplayer, but I do not really trust the security
 606 of mplayer (it crashes too often on strange input), and thus prefer
 607 vlc.  I finally found a way to do it today.  I spent an hour or so
 608 searching the web for recipes and reading the documentation.  The
 609 hardest part was to get rid of the GUI window, but after finding the
 610 dummy interface, the command line finally presented itself:</p>
 611
 612 <blockquote><pre>URL=http://www.ping.uio.no/video/rms-oslo_2009.ogg
 613 SAVEFILE=rms.ogg
 614 DISPLAY= vlc -q $URL \
 615   --sout="#duplicate{dst=std{access=file,url='$SAVEFILE'},dst=nodisplay}" \
 616   --intf=dummy</pre></blockquote>
 617
 618 <p>The command stream the URL and store it in the SAVEFILE by
 619 duplicating the output stream to "nodisplay" and the file, using the
 620 dummy interface.  The dummy interface and the nodisplay output make
 621 sure no X interface is needed.</p>
 622
 623 <p>The cron job then need to start this job with the appropriate URL
 624 and file name to save, sleep for the duration wanted, and then kill
 625 the vlc process with SIGTERM.  Here is a complete script
 626 <tt>vlc-record</tt> to use from <tt>at</tt> or <tt>cron</tt>:</p>
 627
 628 <blockquote><pre>#!/bin/sh
 629 set -e
 630 URL="$1"
 631 SAVEFILE="$2"
 632 DURATION="$3"
 633 DISPLAY= vlc -q "$URL" \
 634   --sout="#duplicate{dst=std{access=file,url='$SAVEFILE'},dst=nodisplay}" \
 635   --intf=dummy < /dev/null > /dev/null 2>&1 &
 636 pid=$!
 637 sleep $DURATION
 638 kill $pid
 639 wait $pid</pre></blockquote>
 640
 641  </div>
 642  <div class="tags">
 643
 644
 645
 646   Tags: <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>, <a href="../../tags/video">video</a>.
 647
 648  </div>
 649 </div>
 650 <div class="padding"></div>
 651
 652 <div class="entry">
 653  <div class="title">
 654  <a href="../../No_patch_is_not_better_than_a_useless_patch.html">No patch is not better than a useless patch</a>
 655  </div>
 656  <div class="date">
 657   2009-04-28 09:30
 658  </div>
 659
 660  <div class="body">
 661
 662 <p>Julien Blache
 663 <a href="http://blog.technologeek.org/2009/04/12/214">claim that no
 664 patch is better than a useless patch</a>.  I completely disagree, as a
 665 patch allow one to discuss a concrete and proposed solution, and also
 666 prove that the issue at hand is important enough for someone to spent
 667 time on fixing it.  No patch do not provide any of these positive
 668 properties.</p>
 669
 670  </div>
 671  <div class="tags">
 672
 673
 674
 675   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 676
 677  </div>
 678 </div>
 679 <div class="padding"></div>
 680
 681 <div class="entry">
 682  <div class="title">
 683  <a href="../../Two_projects_that_have_improved_the_quality_of_free_software_a_lot.html">Two projects that have improved the quality of free software a lot</a>
 684  </div>
 685  <div class="date">
 686   2009-05-02 15:00
 687  </div>
 688
 689  <div class="body">
 690
 691 <p>There are two software projects that have had huge influence on the
 692 quality of free software, and I wanted to mention both in case someone
 693 do not yet know them.</p>
 694
 695 <p>The first one is <a href="http://valgrind.org/">valgrind</a>, a
 696 tool to detect and expose errors in the memory handling of programs.
 697 It is easy to use, all one need to do is to run 'valgrind program',
 698 and it will report any problems on stdout.  It is even better if the
 699 program include debug information.  With debug information, it is able
 700 to report the source file name and line number where the problem
 701 occurs.  It can report things like 'reading past memory block in file
 702 X line N, the memory block was allocated in file Y, line M', and
 703 'using uninitialised value in control logic'.  This tool has made it
 704 trivial to investigate reproducible crash bugs in programs, and have
 705 reduced the number of this kind of bugs in free software a lot.
 706
 707 <p>The second one is
 708 <a href="http://en.wikipedia.org/wiki/Coverity">Coverity</a> which is
 709 a source code checker.  It is able to process the source of a program
 710 and find problems in the logic without running the program.  It
 711 started out as the Stanford Checker and became well known when it was
 712 used to find bugs in the Linux kernel.  It is now a commercial tool
 713 and the company behind it is running
 714 <a href="http://www.scan.coverity.com/">a community service</a> for the
 715 free software community, where a lot of free software projects get
 716 their source checked for free.  Several thousand defects have been
 717 found and fixed so far.  It can find errors like 'lock L taken in file
 718 X line N is never released if exiting in line M', or 'the code in file
 719 Y lines O to P can never be executed'.  The projects included in the
 720 community service project have managed to get rid of a lot of
 721 reliability problems thanks to Coverity.</p>
 722
 723 <p>I believe tools like this, that are able to automatically find
 724 errors in the source, are vital to improve the quality of software and
 725 make sure we can get rid of the crashing and failing software we are
 726 surrounded by today.</p>
 727
 728  </div>
 729  <div class="tags">
 730
 731
 732
 733   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/english">english</a>.
 734
 735  </div>
 736 </div>
 737 <div class="padding"></div>
 738
 739 <div class="entry">
 740  <div class="title">
 741  <a href="../../Debian_boots_quicker_and_quicker.html">Debian boots quicker and quicker</a>
 742  </div>
 743  <div class="date">
 744   2009-06-24 21:40
 745  </div>
 746
 747  <div class="body">
 748
 749 <p>I spent Monday and tuesday this week in London with a lot of the
 750 people involved in the boot system on Debian and Ubuntu, to see if we
 751 could find more ways to speed up the boot system.  This was an Ubuntu
 752 funded
 753 <a href="https://wiki.ubuntu.com/FoundationsTeam/BootPerformance/DebianUbuntuSprint">developer
 754 gathering</a>. It was quite productive.  We also discussed the future
 755 of boot systems, and ways to handle the increasing number of boot
 756 issues introduced by the Linux kernel becoming more and more
 757 asynchronous and event base.  The Ubuntu approach using udev and
 758 upstart might be a good way forward.  Time will show.</p>
 759
 760 <p>Anyway, there are a few ways at the moment to speed up the boot
 761 process in Debian.  All of these should be applied to get a quick
 762 boot:</p>
 763
 764 <ul>
 765
 766 <li>Use dash as /bin/sh.</li>
 767
 768 <li>Disable the init.d/hwclock*.sh scripts and make sure the hardware
 769    clock is in UTC.</li>
 770
 771 <li>Install and activate the insserv package to enable
 772    <a href="http://wiki.debian.org/LSBInitScripts/DependencyBasedBoot">dependency
 773    based boot sequencing</a>, and enable concurrent booting.</li>
 774
 775 </ul>
 776
 777 These points are based on the Google summer of code work done by
 778 <a href="http://initscripts-ng.alioth.debian.org/soc2006-bootsystem/">Carlos
 779 Villegas</a>.
 780
 781 <p>Support for makefile-style concurrency during boot was uploaded to
 782 unstable yesterday.  When we tested it, we were able to cut 6 seconds
 783 from the boot sequence.  It depend on very correct dependency
 784 declaration in all init.d scripts, so I expect us to find edge cases
 785 where the dependences in some scripts are slightly wrong when we start
 786 using this.</p>
 787
 788 <p>On our IRC channel for this effort, #pkg-sysvinit, a new idea was
 789 introduced by Raphael Geissert today, one that could affect the
 790 startup speed as well.  Instead of starting some scripts concurrently
 791 from rcS.d/ and another set of scripts from rc2.d/, it would be
 792 possible to run a of them in the same process.  A quick way to test
 793 this would be to enable insserv and run 'mv /etc/rc2.d/S* /etc/rcS.d/;
 794 insserv'.  Will need to test if that work. :)</p>
 795
 796  </div>
 797  <div class="tags">
 798
 799
 800
 801   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/english">english</a>.
 802
 803  </div>
 804 </div>
 805 <div class="padding"></div>
 806
 807 <div class="entry">
 808  <div class="title">
 809  <a href="../../Taking_over_sysvinit_development.html">Taking over sysvinit development</a>
 810  </div>
 811  <div class="date">
 812   2009-07-22 23:00
 813  </div>
 814
 815  <div class="body">
 816
 817 <p>After several years of frustration with the lack of activity from
 818 the existing sysvinit upstream developer, I decided a few weeks ago to
 819 take over the package and become the new upstream.  The number of
 820 patches to track for the Debian package was becoming a burden, and the
 821 lack of synchronization between the distribution made it hard to keep
 822 the package up to date.</p>
 823
 824 <p>On the new sysvinit team is the SuSe maintainer Dr. Werner Fink,
 825 and my Debian co-maintainer Kel Modderman.  About 10 days ago, I made
 826 a new upstream tarball with version number 2.87dsf (for Debian, SuSe
 827 and Fedora), based on the patches currently in use in these
 828 distributions.  We Debian maintainers plan to move to this tarball as
 829 the new upstream as soon as we find time to do the merge.  Since the
 830 new tarball was created, we agreed with Werner at SuSe to make a new
 831 upstream project at <a href="http://savannah.nongnu.org/">Savannah</a>, and continue
 832 development there.  The project is registered and currently waiting
 833 for approval by the Savannah administrators, and as soon as it is
 834 approved, we will import the old versions from svn and continue
 835 working on the future release.</p>
 836
 837 <p>It is a bit ironic that this is done now, when some of the involved
 838 distributions are moving to upstart as a syvinit replacement.</p>
 839
 840  </div>
 841  <div class="tags">
 842
 843
 844
 845   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 846
 847  </div>
 848 </div>
 849 <div class="padding"></div>
 850
 851 <div class="entry">
 852  <div class="title">
 853  <a href="../../Debian_has_switched_to_dependency_based_boot_sequencing.html">Debian has switched to dependency based boot sequencing</a>
 854  </div>
 855  <div class="date">
 856   2009-07-28 23:50
 857  </div>
 858
 859  <div class="body">
 860
 861 <p>Since this evening, with the upload of sysvinit version 2.87dsf-2,
 862 and the upload of insserv version 1.12.0-10 yesterday, Debian unstable
 863 have been migrated to using dependency based boot sequencing.  This
 864 conclude work me and others have been doing for the last three days.
 865 It feels great to see this finally part of the default Debian
 866 installation.  Now we just need to weed out the last few problems that
 867 are bound to show up, to get everything ready for Squeeze.</p>
 868
 869 <p>The next step is migrating /sbin/init from sysvinit to upstart, and
 870 fixing the more fundamental problem of handing the event based
 871 non-predictable kernel in the early boot.</p>
 872
 873  </div>
 874  <div class="tags">
 875
 876
 877
 878   Tags: <a href="../../tags/debian">debian</a>, <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
 879
 880  </div>
 881 </div>
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 891 <h2>Archive</h2>
 892 <ul>
 893
 894 <li>2009
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 912
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 914 <ul>
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