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5 <title>Petter Reinholdtsen
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14 <a href=
"http://people.skolelinux.org/pere/blog/">Petter Reinholdtsen
</a>
23 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/Testing_if_a_file_system_can_be_used_for_home_directories___.html">Testing if a file system can be used for home directories...
</a></div>
24 <div class=
"date">2010-
08-
08 21:
20</div>
26 <p>A few years ago, I was involved in a project planning to use
27 Windows file servers as home directory servers for Debian
28 Edu/Skolelinux machines. This was thought to be no problem, as the
29 access would be through the SMB network file system protocol, and we
30 knew other sites used SMB with unix and samba as the file server to
31 mount home directories without any problems. But, after months of
32 struggling, we had to conclude that our goal was impossible.
</p>
34 <p>The reason is simply that while SMB can be used for home
35 directories when the file server is Samba running on Unix, this only
36 work because of Samba have some extensions and the fact that the
37 underlying file system is a unix file system. When using a Windows
38 file server, the underlying file system do not have POSIX semantics,
39 and several programs will fail if the users home directory where they
40 want to store their configuration lack POSIX semantics.
</p>
42 <p>As part of this work, I wrote a small C program I want to share
43 with you all, to replicate a few of the problematic applications (like
44 OpenOffice.org and GCompris) and see if the file system was working as
45 it should. If you find yourself in spooky file system land, it might
46 help you find your way out again. This is the fs-test.c source:
</p>
50 * Some tests to check the file system sematics. Used to verify that
51 * CIFS from a windows server do not work properly as a linux home
53 * License: GPL v2 or later
55 * needs libsqlite3-dev and build-essential installed
56 * compile with: gcc -Wall -lsqlite3 -DTEST_SQLITE fs-test.c -o fs-test
59 #define _FILE_OFFSET_BITS
64
60 #define _LARGEFILE_SOURCE
1
61 #define _LARGEFILE64_SOURCE
1
63 #define _GNU_SOURCE /* for asprintf() */
72 #include
<sys/types.h
>
77 * Test sqlite open, as done by gcompris require the libsqlite3-dev
78 * package and linking with -lsqlite3. A more low level test is
80 * See also
<URL: http://www.sqlite.org./faq.html#q5
>.
83 #define CREATE_TABLE_USERS \
84 "CREATE TABLE users (user_id INT UNIQUE, login TEXT, lastname TEXT, firstname TEXT, birthdate TEXT, class_id INT ); "
85 int test_sqlite_open(void) {
87 char *name = "testsqlite.db";
90 int rc = sqlite3_open(name, &db);
92 printf("error: sqlite open of %s failed: %s\n", name, sqlite3_errmsg(db));
98 rc = sqlite3_exec(db,CREATE_TABLE_USERS, NULL,
0, &zErrMsg);
99 if( rc != SQLITE_OK ){
100 printf("error: sqlite table create failed: %s\n", zErrMsg);
104 printf("info: sqlite worked\n");
108 #endif /* TEST_SQLITE */
111 * Demonstrate locking issue found in gcompris using sqlite3. This
112 * work with ext3, but not with cifs server on Windows
2003. This is
113 * done in the sqlite3 library.
115 *
<URL:http://www.cygwin.com/ml/cygwin/
2001-
08/msg00854.html
> and the
116 * POSIX specification
117 *
<URL:http://www.opengroup.org/onlinepubs/
009695399/functions/fcntl.html
>.
119 int test_gcompris_locking(void) {
121 char *name = "testsqlite.db";
123 int fd = open(name, O_RDWR|O_CREAT|O_LARGEFILE,
0644);
124 printf("info: testing fcntl locking\n");
126 fl.l_whence = SEEK_SET;
128 printf(" Read-locking
1 byte from
1073741824");
129 fl.l_start =
1073741824;
132 if (
0 != fcntl(fd, F_SETLK, &fl) ) printf(" - error!\n"); else printf("\n");
134 printf(" Read-locking
510 byte from
1073741826");
135 fl.l_start =
1073741826;
138 if (
0 != fcntl(fd, F_SETLK, &fl) ) printf(" - error!\n"); else printf("\n");
140 printf(" Unlocking
1 byte from
1073741824");
141 fl.l_start =
1073741824;
144 if (
0 != fcntl(fd, F_SETLK, &fl) ) printf(" - error!\n"); else printf("\n");
146 printf(" Write-locking
1 byte from
1073741824");
147 fl.l_start =
1073741824;
150 if (
0 != fcntl(fd, F_SETLK, &fl) ) printf(" - error!\n"); else printf("\n");
152 printf(" Write-locking
510 byte from
1073741826");
153 fl.l_start =
1073741826;
155 if (
0 != fcntl(fd, F_SETLK, &fl) ) printf(" - error!\n"); else printf("\n");
157 printf(" Unlocking
2 byte from
1073741824");
158 fl.l_start =
1073741824;
161 if (
0 != fcntl(fd, F_SETLK, &fl) ) printf(" - error!\n"); else printf("\n");
168 * Test if permissions of freshly created directories allow entries
169 * below them. This was a problem with OpenOffice.org and gcompris.
170 * Mounting with option 'sync' seem to solve this problem while
171 * slowing down file operations.
173 int test_subdirectory_creation(void) {
175 char *path = strdup("test");
178 printf("info: testing subdirectory creation\n");
179 for (level =
0; level < LEVELS; level++) {
180 char *newpath = NULL;
181 if (-
1 == mkdir(path,
0777)) {
182 printf(" error: Unable to create directory '%s': %s\n",
183 path, strerror(errno));
186 asprintf(&newpath, "%s/%s", path, "test");
194 * Test if symlinks can be created. This was a problem detected with
197 int test_symlinks(void) {
198 printf("info: testing symlink creation\n");
200 if (-
1 == symlink("file", "symlink"))
201 printf(" error: Unable to create symlink\n");
205 int main(int argc, char **argv) {
206 printf("Testing POSIX/Unix sematics on file system\n");
208 test_subdirectory_creation();
211 #endif /* TEST_SQLITE */
212 test_gcompris_locking();
217 <p>When everything is working, it should print something like
221 Testing POSIX/Unix sematics on file system
222 info: testing symlink creation
223 info: testing subdirectory creation
225 info: testing fcntl locking
226 Read-locking
1 byte from
1073741824
227 Read-locking
510 byte from
1073741826
228 Unlocking
1 byte from
1073741824
229 Write-locking
1 byte from
1073741824
230 Write-locking
510 byte from
1073741826
231 Unlocking
2 byte from
1073741824
234 <p>I do not remember the exact details of the problems we saw, but one
235 of them was with locking, where if I remember correctly, POSIX allow a
236 read-only lock to be upgraded to a read-write lock without unlocking
237 the read-only lock (while Windows do not). Another was a bug in the
238 CIFS/SMB client implementation in the Linux kernel where directory
239 meta information would be wrong for a fraction of a second, making
240 OpenOffice.org fail to create its deep directory tree because it was
241 not allowed to create files in its freshly created directory.
</p>
243 <p>Anyway, here is a nice tool for your tool box, might you never need
250 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
254 <div class=
"padding"></div>
257 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/Autodetecting_Client_setup_for_roaming_workstations_in_Debian_Edu.html">Autodetecting Client setup for roaming workstations in Debian Edu
</a></div>
258 <div class=
"date">2010-
08-
07 14:
45</div>
261 <a href=
"http://people.skolelinux.org/pere/blog/Debian_Edu_roaming_workstation___at_the_university_of_Oslo.html">tried
262 to install
</a> a Roaming workation profile from Debian Edu/Squeeze
263 while on the university network here at the University of Oslo, and
264 noticed how much had to change to get it operational using the
265 university infrastructure. It was fairly easy, but it occured to me
266 that Debian Edu would improve a lot if I could get the client to
267 connect without any changes at all, and thus let the client configure
268 itself during installation and first boot to use the infrastructure
269 around it. Now I am a huge step further along that road.
</p>
271 <p>With our current squeeze-test packages, I can select the roaming
272 workstation profile and get a working laptop connecting to the
273 university LDAP server for user and group and our active directory
274 servers for Kerberos authentication. All this without any
275 configuration at all during installation. My users home directory got
276 a bookmark in the KDE menu to mount it via SMB, with the correct URL.
277 In short, openldap and sssd is correctly configured. In addition to
278 this, the client look for http://wpad/wpad.dat to configure a web
279 proxy, and when it fail to find it no proxy settings are stored in
280 /etc/environment and /etc/apt/apt.conf. Iceweasel and KDE is
281 configured to look for the same wpad configuration and also do not use
282 a proxy when at the university network. If the machine is moved to a
283 network with such wpad setup, it would automatically use it when DHCP
284 gave it a IP address.
</p>
286 <p>The LDAP server is located using DNS, by first looking for the DNS
287 entry ldap.$domain. If this do not exist, it look for the
288 _ldap._tcp.$domain SRV records and use the first one as the LDAP
289 server. Next, it connects to the LDAP server and search all
290 namingContexts entries for posixAccount or posixGroup objects, and
291 pick the first one as the LDAP base. For Kerberos, a similar
292 algorithm is used to locate the LDAP server, and the realm is the
293 uppercase version of $domain.
</p>
295 <p>So, what is not working, you might ask. SMB mounting my home
296 directory do not work. No idea why, but suspected the incorrect
297 Kerberos settings in /etc/krb5.conf and /etc/samba/smb.conf might be
298 the cause. These are not properly configured during installation, and
299 had to be hand-edited to get the correct Kerberos realm and server,
300 but SMB mounting still do not work. :(
</p>
302 <p>With this automatic configuration in place, I expect a Debian Edu
303 roaming profile installation would be able to automatically detect and
304 connect to any site using LDAP and Kerberos for NSS directory and PAM
305 authentication. It should also work out of the box in a Active
306 Directory environment providing posixAccount and posixGroup objects
307 with UID and GID values.
</p>
309 <p>If you want to help out with implementing these things for Debian
310 Edu, please contact us on debian-edu@lists.debian.org.
</p>
316 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
320 <div class=
"padding"></div>
323 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/Debian_Edu_roaming_workstation___at_the_university_of_Oslo.html">Debian Edu roaming workstation - at the university of Oslo
</a></div>
324 <div class=
"date">2010-
08-
03 23:
30</div>
326 <p>The new roaming workstation profile in Debian Edu/Squeeze is fairly
327 similar to the laptop setup am I working on using Ubuntu for the
328 University of Oslo, and just for the heck of it, I tested today how
329 hard it would be to integrate that profile into the university
330 infrastructure. In this case, it is the university LDAP server,
331 Active Directory Kerberos server and SMB mounting from the Netapp file
334 <p>I was pleasantly surprised that the only three files needed to be
335 changed (/etc/sssd/sssd.conf, /etc/ldap.conf and
336 /etc/mklocaluser.d/
20-debian-edu-config) and one file had to be added
337 (/usr/share/perl5/Debian/Edu_Local.pm), to get the client working.
338 Most of the changes were to get the client to use the university LDAP
339 for NSS and Kerberos server for PAM, but one was to change a hard
340 coded DNS domain name in the mklocaluser hook from .intern to
343 <p>This testing was so encouraging, that I went ahead and adjusted the
344 Debian Edu scripts and setup in subversion to centralise the roaming
345 workstation setup a bit more and avoid the hardcoded DNS domain name,
346 so that when I test this tomorrow, I expect to get away with modifying
347 only /etc/sssd/sssd.conf and /etc/ldap.conf to get it to use the
348 university servers.
</p>
350 <p>My goal is to get the clients to have no hardcoded settings and
351 fetch all their initial setup during installation and first boot, to
352 allow them to be inserted also into environments where the default
353 setup in Debian Edu has been changed or as with the university, where
354 the environment is different but provides the protocols Debian Edu
361 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
365 <div class=
"padding"></div>
368 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/Circular_package_dependencies_harms_apt_recovery.html">Circular package dependencies harms apt recovery
</a></div>
369 <div class=
"date">2010-
07-
27 23:
50</div>
371 <p>I discovered this while doing
372 <a href=
"http://people.skolelinux.org/pere/blog/Automatic_upgrade_testing_from_Lenny_to_Squeeze.html">automated
373 testing of upgrades from Debian Lenny to Squeeze
</a>. A few packages
374 in Debian still got circular dependencies, and it is often claimed
375 that apt and aptitude should be able to handle this just fine, but
376 some times these dependency loops causes apt to fail.
</p>
378 <p>An example is from todays
379 <a href=
"http://people.skolelinux.org/~pere/debian-upgrade-testing//test-20100727-lenny-squeeze-kde-aptitude.txt">upgrade
380 of KDE using aptitude
</a>. In it, a bug in kdebase-workspace-data
381 causes perl-modules to fail to upgrade. The cause is simple. If a
382 package fail to unpack, then only part of packages with the circular
383 dependency might end up being unpacked when unpacking aborts, and the
384 ones already unpacked will fail to configure in the recovery phase
385 because its dependencies are unavailable.
</p>
387 <p>In this log, the problem manifest itself with this error:
</p>
390 dpkg: dependency problems prevent configuration of perl-modules:
391 perl-modules depends on perl (
>=
5.10.1-
1); however:
392 Version of perl on system is
5.10.0-
19lenny
2.
393 dpkg: error processing perl-modules (--configure):
394 dependency problems - leaving unconfigured
397 <p>The perl/perl-modules circular dependency is already
398 <a href=
"http://bugs.debian.org/527917">reported as a bug
</a>, and will
399 hopefully be solved as soon as possible, but it is not the only one,
400 and each one of these loops in the dependency tree can cause similar
401 failures. Of course, they only occur when there are bugs in other
402 packages causing the unpacking to fail, but it is rather nasty when
403 the failure of one package causes the problem to become worse because
404 of dependency loops.
</p>
407 <a href=
"http://lists.debian.org/debian-devel/2010/06/msg00116.html">the
408 tireless effort by Bill Allombert
</a>, the number of circular
410 <a href=
"http://debian.semistable.com/debgraph.out.html">left in Debian
411 is dropping
</a>, and perhaps it will reach zero one day. :)
</p>
413 <p>Todays testing also exposed a bug in
414 <a href=
"http://bugs.debian.org/590605">update-notifier
</a> and
415 <a href=
"http://bugs.debian.org/590604">different behaviour
</a> between
416 apt-get and aptitude, the latter possibly caused by some circular
417 dependency. Reported both to BTS to try to get someone to look at
424 Tags:
<a href=
"http://people.skolelinux.org/pere/blog/tags/debian">debian
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/english">english
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
428 <div class=
"padding"></div>
431 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/First_Debian_Edu_test_release__alpha0__based_on_Squeeze_is_released.html">First Debian Edu test release (alpha0) based on Squeeze is released
</a></div>
432 <div class=
"date">2010-
07-
27 17:
45</div>
434 <p>I just posted this announcement culminating several months of work
435 with the next Debian Edu release. Not nearly done, but one major step
439 <p>This is the first test release based on Squeeze. The focus of this
440 release is to test the user application selection. To have a look,
441 install the standalone profile and let the developers know if the set
442 of installed packages i.e. applications should be modified. If some
443 user application is missing, or if there are some applications that no
444 longer make sense to be included in Debian Edu, please let us know.
445 Also, if a useful application is missing the translation for your
446 language of choice, please let us know too.
</p>
448 <p>In addition, feedback and help to polish the desktop (menus,
449 artwork, starters, etc.) is appreciated. We would like to ship a nice
450 and handy KDE4 desktop targeted for schools out of the box.
</p>
452 <p>The other profiles should be installable, but there is a lot more
453 work left to be done before they are ready, so do not expect to
456 <p>Changes compared to the lenny based version
</p>
459 <li>Everything from Debian Squeeze
461 <li>Desktop environment KDE
4.4 =
> the new KDE desktop in
462 combination with some new artwork
463 <li>Web browser Iceweasel
3.5
464 <li>OpenOffice.org
3.2
465 <li>Educational toolbox GCompris
9.3
466 <li>Music creator Rosegarden
10.04.2
467 <li>Image editor Gimp
2.6.10
468 <li>Virtual universe Celestia
1.6.0
469 <li>Virtual stargazer Stellarium
0.10.4
470 <li>3D modeler Blender
2.49.2 (new application)
471 <li>Video editor Kdenlive
0.7.7 (new application)
473 <li>Now using Kerberos for password checking (migration not finished).
479 <li>SMTP (sender verification)
482 <li>New experimental roaming workstation profile for laptops.
</li>
483 <li>Show welcome page to users when they first log in. The URL is
484 fetched from LDAP.
</li>
485 <li>New LXDE desktop option, in addition to KDE (default) and Gnome.
</li>
486 <li>General cleanup (not finished)
</li>
488 <p>The following features are not working as they should
</p>
491 <li>No web based administration tool for creating users and groups. The
492 scripts ldap-createuser-krb and ldap-add-user-to-group can be used
494 <li>DVD installs are missing debian-installer images for the PXE boot,
495 and do not set up the PXE menu on eth0 because of this. LTSP
496 clients should still boot from eth1 on thin client servers.
</li>
497 <li>The restructured KDE menu is not implemented.
</li>
498 <li>The LDAP server setup need to be reviewed for security.
</li>
499 <li>The LDAP directory structure need to be reworked.
</li>
500 <li>Different sets of packages are installed when using the DVD and the
501 netinst CD. More packages are installed using the netinst CD.
</li>
502 <li>The jackd package fail to install. This is believed to be caused by
503 some ongoing transition, and hopefully should be solved soon. The
504 jackd1 package can be installed manually for those that need it.
</li>
505 <li>Some packages lack translations. See
506 http://wiki.debian.org/DebianEdu/Status/Squeeze for updated status,
507 and help out with translations.
</li>
510 <p>To download this multiarch netinstall release you can use
</p>
513 <li><a href=
"ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso">ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-
6.0.0+edua0-CD.iso
</a></li>
514 <li><a href=
"http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-CD.iso">http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-
6.0.0+edua0-CD.iso
</a></li>
515 <li>rsync -avzP ftp.skolelinux.org::skolelinux-cd/squeeze-alpha/debian-edu-
6.0.0+edua0-CD.iso
</li>
517 <p>To download this multiarch dvd release you can use
</p>
520 <li><a href=
"ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso">ftp://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-
6.0.0+edua0-DVD.iso
</a></li>
521 <li><a href=
"http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-6.0.0+edua0-DVD.iso">http://ftp.skolelinux.org/skolelinux-cd/squeeze-alpha/debian-edu-
6.0.0+edua0-DVD.iso
</a></li>
522 <li>rsync -avzP ftp.skolelinux.org::skolelinux-cd/squeeze-alpha/debian-edu-
6.0.0+edua0-DVD.iso
</li>
525 <p>There is no source DVD available yet. It will be prepared when we
526 get closer to the final release.
</p>
528 <p>The MD5SUM of these images are
</p>
531 <li>3dbf45d59f42a53518b6e3c9ec3b5eb6 debian-edu-
6.0.0+edua0-CD.iso
</li>
532 <li>22f2cbfce281d1c6e478be452638675d debian-edu-
6.0.0+edua0-DVD.iso
</li>
535 <p>The SHA1SUM of these images are
</p>
537 <li>c53d1b69b40cf37cd27aefaf33f6f6a3821bedf0 debian-edu-
6.0.0+edua0-CD.iso
</li>
538 <li>2ec29d7db676d59d32197b05c277ffe16348376c debian-edu-
6.0.0+edua0-DVD.iso
</li>
540 <p>How to report bugs:
541 http://wiki.debian.org/DebianEdu/HowTo/ReportBugsInBugzilla
</p>
543 <p>Please direct replies to debian-edu@lists.debian.org
</p>
550 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
554 <div class=
"padding"></div>
557 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/One_step_closer_to_single_signon_in_Debian_Edu.html">One step closer to single signon in Debian Edu
</a></div>
558 <div class=
"date">2010-
07-
25 10:
00</div>
560 <p>The last few months me and the other Debian Edu developers have
561 been working hard to get the Debian/Squeeze based version of Debian
562 Edu/Skolelinux into shape. This future version will use Kerberos for
563 authentication, and services are slowly migrated to single signon,
564 getting rid of password questions one at the time.
</p>
566 <p>It will also feature a roaming workstation profile with local home
567 directory, for laptops that are only some times on the Skolelinux
568 network, and for this profile a shortcut is created in Gnome and KDE
569 to gain access to the users home directory on the file server. This
570 shortcut uses SMB at the moment, and yesterday I had time to test if
571 SMB mounting had started working in KDE after we added the cifs-utils
572 package. I was pleasantly surprised how well it worked.
</p>
574 <p>Thanks to the recent changes to our samba configuration to get it
575 to use Kerberos for authentication, there were no question about user
576 password when mounting the SMB volume. A simple click on the shortcut
577 in the KDE menu, and a window with the home directory popped
580 <p>One step closer to a single signon solution out of the box in
581 Debian Edu. We already had PAM, LDAP, IMAP and SMTP in place, and now
582 also Samba. Next step is Cups and hopefully also NFS.
</p>
584 <p>We had planned a alpha0 release of Debian Edu for today, but thanks
585 to the autobuilder administrators for some architectures being slow to
586 sign packages, we are still missing the fixed LTSP package we need for
587 the release. It was uploaded three days ago with urgency=high, and if
588 it had entered testing yesterday we would have been able to test it in
589 time for a alpha0 release today. As the binaries for ia64 and powerpc
590 still not uploaded to the Debian archive, we need to delay the alpha
591 release another day.
</p>
593 <p>If you want to help out with implementing Kerberos for Debian Edu,
594 please contact us on debian-edu@lists.debian.org.
</p>
600 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet
</a>.
604 <div class=
"padding"></div>
607 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/Digitale_restriksjonsmekanismer_fikk_meg_til____slutte____kj__pe_musikk.html">Digitale restriksjonsmekanismer fikk meg til å slutte å kjøpe musikk
</a></div>
608 <div class=
"date">2010-
07-
22 23:
50</div>
610 <p>For mange år siden slutte jeg å kjøpe musikk-CDer. Årsaken var at
611 musikkbransjen var godt i gang med å selge platene sine med DRM som
612 gjorde at jeg ikke fikk spilt av musikken jeg kjøpte på utstyret jeg
613 hadde tilgjengelig, dvs. min datamaskin. Det var umulig å se på en
614 plate om den var ødelagt eller ikke, og jeg hadde jo allerede en
615 anseelig samling med plater, så jeg bestemme meg for å slutte å gi
616 penger til en bransje som åpenbart ikke respekterte meg.
</p>
618 <p>Jeg har mange titalls dager med musikk på CD i dag. Det meste er
619 lagt i et stort arkiv som kan spilles av fra husets datamaskiner (har
620 ikke rukket rippe alt). Jeg ser dermed ikke behovet for å skaffe mer
621 musikk. De fleste av mine favoritter er i hus, og jeg er dermed godt
624 <p>Hvis musikkbransjen ønsker mine penger, så må de demonstrere at de
625 setter pris på meg som kunde, og ikke skremme meg bort med DRM og
626 antydninger om at kundene er kriminelle.
</p>
628 <p>Filmbransjen er like ille, men mens musikk gjerne varer lenge, er
629 filmer mer ferskvare. Har dermed ikke helt sluttet å kjøpe filmer, men
630 holder meg til DVD-filmer som kan spilles av på mine Linuxbokser.
631 Kommer neppe til å ta i bruk Blueray, og ei heller de nye DRM-greiene
632 «Ultraviolet» som be annonsert her om dagen.
</p>
638 Tags:
<a href=
"http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/norsk">norsk
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/personvern">personvern
</a>.
642 <div class=
"padding"></div>
645 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/OpenStreetmap_one_step_closer_to_having_routing_on_its_front_page.html">OpenStreetmap one step closer to having routing on its front page
</a></div>
646 <div class=
"date">2010-
07-
18 16:
45</div>
649 <a href=
"http://feedproxy.google.com/~r/Opengeodata/~3/wUTCzDZk3lc/project-of-the-week-which-way-home">todays
650 opengeodata blog entry
</a>, I just discovered that the
651 OpenStreetmap.org site have gotten
652 <a href=
"http://nroets.dev.openstreetmap.org/demo/index.html?layers=B000FTFTT">support
653 for calculating routes
</a>. The support is still experimental and
654 only available from the development server, until more experience is
655 gathered on the user interface and any scalability issues.
</p>
657 <p>Earlier, the routing I knew about using the OpenStreetmap.org data
658 was provided by
<a href=
"http://maps.cloudmade.com/">Cloudmade
</a>,
659 but having it on the main page is required to make everyone aware of
660 the issue. I've had people reject Openstreetmap.org as a viable
661 alternative for them because the front page lacked routing support,
662 and I hope their needs will be catered for when routing show up on the
663 www.openstreetmap.org front page.
</p>
669 Tags:
<a href=
"http://people.skolelinux.org/pere/blog/tags/english">english
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/kart">kart
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/web">web
</a>.
673 <div class=
"padding"></div>
676 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/What_are_they_searching_for___PowerDNS_and_ISC_DHCP_in_LDAP.html">What are they searching for - PowerDNS and ISC DHCP in LDAP
</a></div>
677 <div class=
"date">2010-
07-
17 21:
00</div>
680 <a href=
"http://people.skolelinux.org/pere/blog/Time_for_new__LDAP_schemas_replacing_RFC_2307_.html">followup
</a>
682 <a href=
"http://people.skolelinux.org/pere/blog/Idea_for_a_change_to_LDAP_schemas_allowing_DNS_and_DHCP_info_to_be_combined_into_one_object.html">previous
684 <a href=
"http://people.skolelinux.org/pere/blog/Combining_PowerDNS_and_ISC_DHCP_LDAP_objects.html">merging
685 all
</a> the computer related LDAP objects in Debian Edu.
</p>
687 <p>As a step to try to see if it possible to merge the DNS and DHCP
688 LDAP objects, I have had a look at how the packages pdns-backend-ldap
689 and dhcp3-server-ldap in Debian use the LDAP server. The two
690 implementations are quite different in how they use LDAP.
</p>
692 To get this information, I started slapd with debugging enabled and
693 dumped the debug output to a file to get the LDAP searches performed
694 on a Debian Edu main-server. Here is a summary.
696 <p><strong>powerdns
</strong></p>
698 <a href=
"http://www.linuxnetworks.de/doc/index.php/PowerDNS_LDAP_Backend">Clues
699 on how to
</a> set up PowerDNS to use a LDAP backend is available on
702 <p>PowerDNS have two modes of operation using LDAP as its backend.
703 One "strict" mode where the forward and reverse DNS lookups are done
704 using the same LDAP objects, and a "tree" mode where the forward and
705 reverse entries are in two different subtrees in LDAP with a structure
706 based on the DNS names, as in tjener.intern and
707 2.2.0.10.in-addr.arpa.
</p>
709 <p>In tree mode, the server is set up to use a LDAP subtree as its
710 base, and uses a "base" scoped search for the DNS name by adding
711 "dc=tjener,dc=intern," to the base with a filter for
712 "(associateddomain=tjener.intern)" for the forward entry and
713 "dc=
2,dc=
2,dc=
0,dc=
10,dc=in-addr,dc=arpa," with a filter for
714 "(associateddomain=
2.2.0.10.in-addr.arpa)" for the reverse entry. For
715 forward entries, it is looking for attributes named dnsttl, arecord,
716 nsrecord, cnamerecord, soarecord, ptrrecord, hinforecord, mxrecord,
717 txtrecord, rprecord, afsdbrecord, keyrecord, aaaarecord, locrecord,
718 srvrecord, naptrrecord, kxrecord, certrecord, dsrecord, sshfprecord,
719 ipseckeyrecord, rrsigrecord, nsecrecord, dnskeyrecord, dhcidrecord,
720 spfrecord and modifytimestamp. For reverse entries it is looking for
721 the attributes dnsttl, arecord, nsrecord, cnamerecord, soarecord,
722 ptrrecord, hinforecord, mxrecord, txtrecord, rprecord, aaaarecord,
723 locrecord, srvrecord, naptrrecord and modifytimestamp. The equivalent
724 ldapsearch commands could look like this:
</p>
728 -b dc=tjener,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no \
729 -s base -x '(associateddomain=tjener.intern)' dNSTTL aRecord nSRecord \
730 cNAMERecord sOARecord pTRRecord hInfoRecord mXRecord tXTRecord \
731 rPRecord aFSDBRecord KeyRecord aAAARecord lOCRecord sRVRecord \
732 nAPTRRecord kXRecord certRecord dSRecord sSHFPRecord iPSecKeyRecord \
733 rRSIGRecord nSECRecord dNSKeyRecord dHCIDRecord sPFRecord modifyTimestamp
736 -b dc=
2,dc=
2,dc=
0,dc=
10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no \
737 -s base -x '(associateddomain=
2.2.0.10.in-addr.arpa)'
738 dnsttl, arecord, nsrecord, cnamerecord soarecord ptrrecord \
739 hinforecord mxrecord txtrecord rprecord aaaarecord locrecord \
740 srvrecord naptrrecord modifytimestamp
743 <p>In Debian Edu/Lenny, the PowerDNS tree mode is used with
744 ou=hosts,dc=skole,dc=skolelinux,dc=no as the base, and these are two
745 example LDAP objects used there. In addition to these objects, the
746 parent objects all th way up to ou=hosts,dc=skole,dc=skolelinux,dc=no
750 dn: dc=tjener,dc=intern,ou=hosts,dc=skole,dc=skolelinux,dc=no
752 objectclass: dnsdomain
753 objectclass: domainrelatedobject
756 associateddomain: tjener.intern
758 dn: dc=
2,dc=
2,dc=
0,dc=
10,dc=in-addr,dc=arpa,ou=hosts,dc=skole,dc=skolelinux,dc=no
760 objectclass: dnsdomain2
761 objectclass: domainrelatedobject
763 ptrrecord: tjener.intern
764 associateddomain:
2.2.0.10.in-addr.arpa
767 <p>In strict mode, the server behaves differently. When looking for
768 forward DNS entries, it is doing a "subtree" scoped search with the
769 same base as in the tree mode for a object with filter
770 "(associateddomain=tjener.intern)" and requests the attributes dnsttl,
771 arecord, nsrecord, cnamerecord, soarecord, ptrrecord, hinforecord,
772 mxrecord, txtrecord, rprecord, aaaarecord, locrecord, srvrecord,
773 naptrrecord and modifytimestamp. For reverse entires it also do a
774 subtree scoped search but this time the filter is "(arecord=
10.0.2.2)"
775 and the requested attributes are associateddomain, dnsttl and
776 modifytimestamp. In short, in strict mode the objects with ptrrecord
777 go away, and the arecord attribute in the forward object is used
780 <p>The forward and reverse searches can be simulated using ldapsearch
784 ldapsearch -h ldap -b ou=hosts,dc=skole,dc=skolelinux,dc=no -s sub -x \
785 '(associateddomain=tjener.intern)' dNSTTL aRecord nSRecord \
786 cNAMERecord sOARecord pTRRecord hInfoRecord mXRecord tXTRecord \
787 rPRecord aFSDBRecord KeyRecord aAAARecord lOCRecord sRVRecord \
788 nAPTRRecord kXRecord certRecord dSRecord sSHFPRecord iPSecKeyRecord \
789 rRSIGRecord nSECRecord dNSKeyRecord dHCIDRecord sPFRecord modifyTimestamp
791 ldapsearch -h ldap -b ou=hosts,dc=skole,dc=skolelinux,dc=no -s sub -x \
792 '(arecord=
10.0.2.2)' associateddomain dnsttl modifytimestamp
795 <p>In addition to the forward and reverse searches , there is also a
796 search for SOA records, which behave similar to the forward and
799 <p>A thing to note with the PowerDNS behaviour is that it do not
800 specify any objectclass names, and instead look for the attributes it
801 need to generate a DNS reply. This make it able to work with any
802 objectclass that provide the needed attributes.
</p>
804 <p>The attributes are normally provided in the cosine (RFC
1274) and
805 dnsdomain2 schemas. The latter is used for reverse entries like
806 ptrrecord and recent DNS additions like aaaarecord and srvrecord.
</p>
808 <p>In Debian Edu, we have created DNS objects using the object classes
809 dcobject (for dc), dnsdomain or dnsdomain2 (structural, for the DNS
810 attributes) and domainrelatedobject (for associatedDomain). The use
811 of structural object classes make it impossible to combine these
812 classes with the object classes used by DHCP.
</p>
814 <p>There are other schemas that could be used too, for example the
815 dnszone structural object class used by Gosa and bind-sdb for the DNS
816 attributes combined with the domainrelatedobject object class, but in
817 this case some unused attributes would have to be included as well
818 (zonename and relativedomainname).
</p>
820 <p>My proposal for Debian Edu would be to switch PowerDNS to strict
821 mode and not use any of the existing objectclasses (dnsdomain,
822 dnsdomain2 and dnszone) when one want to combine the DNS information
823 with DHCP information, and instead create a auxiliary object class
824 defined something like this (using the attributes defined for
825 dnsdomain and dnsdomain2 or dnszone):
</p>
828 objectclass ( some-oid NAME 'dnsDomainAux'
831 MAY ( ARecord $ MDRecord $ MXRecord $ NSRecord $ SOARecord $ CNAMERecord $
832 DNSTTL $ DNSClass $ PTRRecord $ HINFORecord $ MINFORecord $
833 TXTRecord $ SIGRecord $ KEYRecord $ AAAARecord $ LOCRecord $
834 NXTRecord $ SRVRecord $ NAPTRRecord $ KXRecord $ CERTRecord $
835 A6Record $ DNAMERecord
839 <p>This will allow any object to become a DNS entry when combined with
840 the domainrelatedobject object class, and allow any entity to include
841 all the attributes PowerDNS wants. I've sent an email to the PowerDNS
842 developers asking for their view on this schema and if they are
843 interested in providing such schema with PowerDNS, and I hope my
844 message will be accepted into their mailing list soon.
</p>
846 <p><strong>ISC dhcp
</strong></p>
848 <p>The DHCP server searches for specific objectclass and requests all
849 the object attributes, and then uses the attributes it want. This
850 make it harder to figure out exactly what attributes are used, but
851 thanks to the working example in Debian Edu I can at least get an idea
852 what is needed without having to read the source code.
</p>
854 <p>In the DHCP server configuration, the LDAP base to use and the
855 search filter to use to locate the correct dhcpServer entity is
856 stored. These are the relevant entries from
857 /etc/dhcp3/dhcpd.conf:
</p>
860 ldap-base-dn "dc=skole,dc=skolelinux,dc=no";
861 ldap-dhcp-server-cn "dhcp";
864 <p>The DHCP server uses this information to nest all the DHCP
865 configuration it need. The cn "dhcp" is located using the given LDAP
866 base and the filter "(&(objectClass=dhcpServer)(cn=dhcp))". The
867 search result is this entry:
</p>
870 dn: cn=dhcp,dc=skole,dc=skolelinux,dc=no
873 objectClass: dhcpServer
874 dhcpServiceDN: cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
877 <p>The content of the dhcpServiceDN attribute is next used to locate the
878 subtree with DHCP configuration. The DHCP configuration subtree base
879 is located using a base scope search with base "cn=DHCP
880 Config,dc=skole,dc=skolelinux,dc=no" and filter
881 "(&(objectClass=dhcpService)(|(dhcpPrimaryDN=cn=dhcp,dc=skole,dc=skolelinux,dc=no)(dhcpSecondaryDN=cn=dhcp,dc=skole,dc=skolelinux,dc=no)))".
882 The search result is this entry:
</p>
885 dn: cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
888 objectClass: dhcpService
889 objectClass: dhcpOptions
890 dhcpPrimaryDN: cn=dhcp, dc=skole,dc=skolelinux,dc=no
891 dhcpStatements: ddns-update-style none
892 dhcpStatements: authoritative
893 dhcpOption: smtp-server code
69 = array of ip-address
894 dhcpOption: www-server code
72 = array of ip-address
895 dhcpOption: wpad-url code
252 = text
898 <p>Next, the entire subtree is processed, one level at the time. When
899 all the DHCP configuration is loaded, it is ready to receive requests.
900 The subtree in Debian Edu contain objects with object classes
901 top/dhcpService/dhcpOptions, top/dhcpSharedNetwork/dhcpOptions,
902 top/dhcpSubnet, top/dhcpGroup and top/dhcpHost. These provide options
903 and information about netmasks, dynamic range etc. Leaving out the
904 details here because it is not relevant for the focus of my
905 investigation, which is to see if it is possible to merge dns and dhcp
906 related computer objects.
</p>
908 <p>When a DHCP request come in, LDAP is searched for the MAC address
909 of the client (
00:
00:
00:
00:
00:
00 in this example), using a subtree
910 scoped search with "cn=DHCP Config,dc=skole,dc=skolelinux,dc=no" as
911 the base and "(&(objectClass=dhcpHost)(dhcpHWAddress=ethernet
912 00:
00:
00:
00:
00:
00))" as the filter. This is what a host object look
916 dn: cn=hostname,cn=group1,cn=THINCLIENTS,cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
919 objectClass: dhcpHost
920 dhcpHWAddress: ethernet
00:
00:
00:
00:
00:
00
921 dhcpStatements: fixed-address hostname
924 <p>There is less flexiblity in the way LDAP searches are done here.
925 The object classes need to have fixed names, and the configuration
926 need to be stored in a fairly specific LDAP structure. On the
927 positive side, the invidiual dhcpHost entires can be anywhere without
928 the DN pointed to by the dhcpServer entries. The latter should make
929 it possible to group all host entries in a subtree next to the
930 configuration entries, and this subtree can also be shared with the
931 DNS server if the schema proposed above is combined with the dhcpHost
932 structural object class.
934 <p><strong>Conclusion
</strong></p>
936 <p>The PowerDNS implementation seem to be very flexible when it come
937 to which LDAP schemas to use. While its "tree" mode is rigid when it
938 come to the the LDAP structure, the "strict" mode is very flexible,
939 allowing DNS objects to be stored anywhere under the base cn specified
940 in the configuration.
</p>
942 <p>The DHCP implementation on the other hand is very inflexible, both
943 regarding which LDAP schemas to use and which LDAP structure to use.
944 I guess one could implement ones own schema, as long as the
945 objectclasses and attributes have the names used, but this do not
946 really help when the DHCP subtree need to have a fairly fixed
949 <p>Based on the observed behaviour, I suspect a LDAP structure like
950 this might work for Debian Edu:
</p>
954 cn=machine-info (dhcpService) - dhcpServiceDN points here
956 cn=dhcp-internal (dhcpSharedNetwork/dhcpOptions)
957 cn=
10.0.2.0 (dhcpSubnet)
958 cn=group1 (dhcpGroup/dhcpOptions)
959 cn=dhcp-thinclients (dhcpSharedNetwork/dhcpOptions)
960 cn=
192.168.0.0 (dhcpSubnet)
961 cn=group1 (dhcpGroup/dhcpOptions)
962 ou=machines - PowerDNS base points here
963 cn=hostname (dhcpHost/domainrelatedobject/dnsDomainAux)
966 <P>This is not tested yet. If the DHCP server require the dhcpHost
967 entries to be in the dhcpGroup subtrees, the entries can be stored
968 there instead of a common machines subtree, and the PowerDNS base
969 would have to be moved one level up to the machine-info subtree.
</p>
971 <p>The combined object under the machines subtree would look something
975 dn: dc=hostname,ou=machines,cn=machine-info,dc=skole,dc=skolelinux,dc=no
978 objectClass: dhcpHost
979 objectclass: domainrelatedobject
980 objectclass: dnsDomainAux
981 associateddomain: hostname.intern
983 dhcpHWAddress: ethernet
00:
00:
00:
00:
00:
00
984 dhcpStatements: fixed-address hostname.intern
987 </p>One could even add the LTSP configuration associated with a given
988 machine, as long as the required attributes are available in a
989 auxiliary object class.
</p>
995 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/ldap">ldap
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
999 <div class=
"padding"></div>
1002 <div class=
"title"><a href=
"http://people.skolelinux.org/pere/blog/Combining_PowerDNS_and_ISC_DHCP_LDAP_objects.html">Combining PowerDNS and ISC DHCP LDAP objects
</a></div>
1003 <div class=
"date">2010-
07-
14 23:
45</div>
1005 <p>For a while now, I have wanted to find a way to change the DNS and
1006 DHCP services in Debian Edu to use the same LDAP objects for a given
1007 computer, to avoid the possibility of having a inconsistent state for
1008 a computer in LDAP (as in DHCP but no DNS entry or the other way
1009 around) and make it easier to add computers to LDAP.
</p>
1011 <p>I've looked at how powerdns and dhcpd is using LDAP, and using this
1012 information finally found a solution that seem to work.
</p>
1014 <p>The old setup required three LDAP objects for a given computer.
1015 One forward DNS entry, one reverse DNS entry and one DHCP entry. If
1016 we switch powerdns to use its strict LDAP method (ldap-method=strict
1017 in pdns-debian-edu.conf), the forward and reverse DNS entries are
1018 merged into one while making it impossible to transfer the reverse map
1019 to a slave DNS server.
</p>
1021 <p>If we also replace the object class used to get the DNS related
1022 attributes to one allowing these attributes to be combined with the
1023 dhcphost object class, we can merge the DNS and DHCP entries into one.
1024 I've written such object class in the dnsdomainaux.schema file (need
1025 proper OIDs, but that is a minor issue), and tested the setup. It
1028 <p>With this test setup in place, we can get away with one LDAP object
1029 for both DNS and DHCP, and even the LTSP configuration I suggested in
1030 an earlier email. The combined LDAP object will look something like
1034 dn: cn=hostname,cn=group1,cn=THINCLIENTS,cn=DHCP Config,dc=skole,dc=skolelinux,dc=no
1036 objectClass: dhcphost
1037 objectclass: domainrelatedobject
1038 objectclass: dnsdomainaux
1039 associateddomain: hostname.intern
1040 arecord:
10.11.12.13
1041 dhcphwaddress: ethernet
00:
00:
00:
00:
00:
00
1042 dhcpstatements: fixed-address hostname
1046 <p>The DNS server uses the associateddomain and arecord entries, while
1047 the DHCP server uses the dhcphwaddress and dhcpstatements entries
1048 before asking DNS to resolve the fixed-adddress. LTSP will use
1049 dhcphwaddress or associateddomain and the ldapconfig* attributes.
</p>
1051 <p>I am not yet sure if I can get the DHCP server to look for its
1052 dhcphost in a different location, to allow us to put the objects
1053 outside the "DHCP Config" subtree, but hope to figure out a way to do
1054 that. If I can't figure out a way to do that, we can still get rid of
1055 the hosts subtree and move all its content into the DHCP Config tree
1056 (which probably should be renamed to be more related to the new
1057 content. I suspect cn=dnsdhcp,ou=services or something like that
1058 might be a good place to put it.
</p>
1060 <p>If you want to help out with implementing this for Debian Edu,
1061 please contact us on debian-edu@lists.debian.org.
</p>
1067 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>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/ldap">ldap
</a>,
<a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug
</a>.
1071 <div class=
"padding"></div>
1073 <p style=
"text-align: right;"><a href=
"index.rss"><img src=
"http://people.skolelinux.org/pere/blog/xml.gif" alt=
"RSS feed" width=
"36" height=
"14"></a></p>
1087 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/01/">January (
2)
</a></li>
1089 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/02/">February (
1)
</a></li>
1091 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/03/">March (
3)
</a></li>
1093 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/04/">April (
3)
</a></li>
1095 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/05/">May (
9)
</a></li>
1097 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/06/">June (
14)
</a></li>
1099 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/07/">July (
12)
</a></li>
1101 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2010/08/">August (
3)
</a></li>
1108 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/01/">January (
8)
</a></li>
1110 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/02/">February (
8)
</a></li>
1112 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/03/">March (
12)
</a></li>
1114 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/04/">April (
10)
</a></li>
1116 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/05/">May (
9)
</a></li>
1118 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/06/">June (
3)
</a></li>
1120 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/07/">July (
4)
</a></li>
1122 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/08/">August (
3)
</a></li>
1124 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/09/">September (
1)
</a></li>
1126 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/10/">October (
2)
</a></li>
1128 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/11/">November (
3)
</a></li>
1130 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2009/12/">December (
3)
</a></li>
1137 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2008/11/">November (
5)
</a></li>
1139 <li><a href=
"http://people.skolelinux.org/pere/blog/archive/2008/12/">December (
7)
</a></li>
1150 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/3d-printer">3d-printer (
11)
</a></li>
1152 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/amiga">amiga (
1)
</a></li>
1154 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/aros">aros (
1)
</a></li>
1156 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/bootsystem">bootsystem (
10)
</a></li>
1158 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/debian">debian (
35)
</a></li>
1160 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/debian edu">debian edu (
39)
</a></li>
1162 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/english">english (
54)
</a></li>
1164 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (
1)
</a></li>
1166 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/fildeling">fildeling (
8)
</a></li>
1168 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/kart">kart (
3)
</a></li>
1170 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/ldap">ldap (
8)
</a></li>
1172 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/lenker">lenker (
1)
</a></li>
1174 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/ltsp">ltsp (
1)
</a></li>
1176 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/multimedia">multimedia (
5)
</a></li>
1178 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/norsk">norsk (
71)
</a></li>
1180 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/nuug">nuug (
91)
</a></li>
1182 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett (
14)
</a></li>
1184 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/personvern">personvern (
14)
</a></li>
1186 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/reprap">reprap (
10)
</a></li>
1188 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/rss">rss (
1)
</a></li>
1190 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet (
10)
</a></li>
1192 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/sitesummary">sitesummary (
3)
</a></li>
1194 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/standard">standard (
13)
</a></li>
1196 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/stavekontroll">stavekontroll (
1)
</a></li>
1198 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/video">video (
10)
</a></li>
1200 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/vitenskap">vitenskap (
1)
</a></li>
1202 <li><a href=
"http://people.skolelinux.org/pere/blog/tags/web">web (
7)
</a></li>
1208 <p style=
"text-align: right">
1209 Created by
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