Monthly Archives: December 2008

Good, old holiday cheers

Jim Perrin put an impressive ASCII Christmas tree on Planet CentOS.  This reminded me of my own very old ASCII snowman I used to place in motd of a Solaris workstation during holiday seasons.

-rw-r-----   1 yagi2    yagi         661 Dec 17  1998 holi

$cat holi

                _XXX_      .    .       .  .    .  .   .     .  .
               / """ \    .    .    .   .      . .    .   .      .
              {  0 0  3         .  .     .     .     .        .
              {   <   3    .  .    *** HAPPY HOLIDAYS ***   .   .
               \  V  /      .  .  .  .    .   .    ..   .   . .   .
               &&&&&&&    ..   . .     .     .  .     .     .   .
              /    &  \       .    ..    .  .  .   .    .     .
             /    &    \    .   .     .    .  .  ..    .   .    .
            BB   &    )))     .   .      .     .    .     .  .     .
            \          /
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Clean that Inbox

Like many other people, I use Linux as a backup server.  The other day, I noticed that daily incremental backup of one of the Windows machines was well over 1 GB even on the day the user was mostly idle.  The only thing the user was doing was … e-mailing.  Aha! (heard the bell?)  It must be that inflated Inbox.

Mozilla-based mail clients like Thunderbird and Seamonkey mail do not physically remove messages that user deletes.  Instead they are only tagged “deleted”.  This is true even after the Trash folder is emptied.  The [supposedly] deleted mails get [really] deleted when Inbox (or any folder for that matter) is compacted.

I went to the blasted machine and did just that and the Inbox went from > 1 GB to a fraction of its original size.

Of course, this is not just Windows.  Huge mail folders can potentially cause trouble and also degrade the performance of the client.  The best strategy to prevent this is to set up an automatic clean up.  In Thunderbird, go to Edit -> Preferences -> Advanced -> Network & Disk Space and then enable the “Compact folders when it will save over…KB” option.

Getting kino to work on CentOS-5

One of the many things I use Linux for at work is to edit movies.  No, not that kind of movies you are thinking about … this is strictly for science work.  Anyway, the first step is to transfer video from a camcorder connected through a firewire port using kino.  I am doing this on a machine running Fedora Core 6.  I attempted to do the work on a CentOS-5 box.  However, going to the capture mode on kino produces an error:

*raw1394 kernel module not loaded or failure to read/write .....

Long story short, this is a known issue, and the kino web site offers a couple of workarounds. I am going to summarize a CentOS version of these workarounds.

Method 1 — requires a kernel from the centosplus repository

(1) Edit /etc/modprobe.d/blacklist-firewire and comment out blacklist firewire-ohci
(2) Reboot
(or run modprobe firewire-ohci to achieve the same without reboot)
(3) Connect the camcorder
(4) Step (3) creates /dev/fw? (? = 0, 1, etc). Change the owner to the logged-in user.
(5) Start kino and go to Capture. Press the Capture button.

Method 2 — Use if Method 1 does not work

(1) Install ieee1394 from the ATrpms repository. Refer to the CentOS Wiki Repository article for the instruction.
(2) Download the kmod-ieee1394 package frpm the ELRepo repository and install it using the rpm -Uvh command. There is no need to reinstall this kernel module upon kernel update.
(3) Download packages libraw1394_8 and libraw1394 from my collection and install them as in (2).
(4) Edit /etc/modprobe.d/blacklist and add these lines:
blacklist firewire_core
blacklist firewire_ohci
(5) Reboot
(6) Chenge the ownership of /dev/raw1394 to the logged in user.

Counting [on] CentOS Wiki

CentOS Wiki is filled with information and is one of the most frequently used resources available to CentOS users. But, little known is its statistics page:

http://wiki.centos.org/PageHits

According to Ralph, this page is created through a macro called “PageHits” but not all the details as to how this works are known. Anyway, let’s take a look at some of the top entries as of Dec 05, 2008.

This page shows how often a page was requested since the beginning of
logging. It has no intelligence, every view counts as hit.

 1. 732352 FrontPage
 2. 268550 HowTos
 3. 263042 Repositories
 4. 217961 Repositories/RPMForge
 5. 158478 TipsAndTricks
 6. 136617 FAQ
 7. 112780 HowTos/JavaOnCentOS
 8. 105514 FAQ/CentOS5
 9. 104275 HowTos/Xen/InstallingCentOSDomU
10. 102457 Repositories/CentOSPlus
11.  88726 Manuals/ReleaseNotes/CentOS5.1
12.  77033 Manuals/ReleaseNotes/CentOS5.0
13.  64338 PackageManagement/Yum
14.  64289 HowTos/Custom Kernel
15.  59413 HowTos/I need the Kernel Source
16.  58947 PackageManagement/Yum/Priorities
17.  57351 Manuals
18.  56419 Manuals/ReleaseNotes/CentOS5.2
19.  54229 HowTos/FreeNX
20.  49854 HowTos/PackageManagement/YumOnRHEL
21.  48016 FAQ/General
22.  42976 TipsAndTricks/NTFSPartitions
23.  42750 HowTos/Network/IPTables
24.  41817 TipsAndTricks/YumAndRPM
25.  41442 RecentChanges
26.  40885 HowTos/Nagios
27.  40669 GettingHelp
28.  40373 HowTos/Subversion
29.  37791 TipsAndTricks/WindowsShares
30.  30907 TipsAndTricks/Xen
32.  28906 TipsAndTricks/KickStart
33.  28127 FAQ/CentOS4
34.  27719 HowTos/MigrationGuide/ServerCD 4.4 to 5
35.  27660 Manuals/ReleaseNotes/CentOS5.1/Japanese
36.  26997 TipsAndTricks/VMWare Server
37.  26659 HardwareList


no intelligence … Hmmm, sounds familiar?  Let’s do some analysis. Not so surprisingly, the FrontPage is by far the most often visited page. Also, I knew that the Repositories article was very popular, and that indeed seems to be the case. Things like FAQ or ReleaseNotes are expected to get a lot of hits. What was interesting to me (as a Japanese) was that, among the localized ReleaseNotes, the Japanese version ranked No,1.  This is either because there are so many CentOS users in Japan or the Japanese people do not want to read English (or both).

The kernel-related pages are also well visited despite the fact custome kernels are not supported by the CentOS team.  Alan‘s efforts among others are well paid for.  Ned‘s IPTables is quite popular, too.  Note this page is relatively young compared to others.

My own small contributions, NTFS and WindowsShares, are listed there indiating a good number of CentOS users still stuck with the other OS.