March 19th Meeting Notes

Another great meeting with 13 in attendance.  As promised, Taos provided the grea pizza, soda, and cookies.  Clint led off the evening with Dvdisaster based on a article in Linux Magazine issue 171/2015 "Lifebuoy". http://www.linux-magazine.com/Issues/2015/171/Dvdisaster.  He has spend quite of bit of time in exploring how to use it to recover DVDs and CD's that have errors in reading.  He started out with purposely nicking a CD with a knife, damaging it, only to find that DVDisater couldn't fix it.  He then tested for creating read error my "smugging" the shiny side (read side) with a hersey kiss.  He found that this type of "read error" can be fixed and he showed a series of screen shots of each of the operations.  To prepare for the eventual recover of a DVD/CD, you must first archive an error correction file while the media is still good or "new".  This is done by first scanning it, then read'ing it to create a medium.iso, and then create'ing the error file (medium.ecc).  Once you have the .ecc file, you can delete the medium.iso as it is basically the same as the original iso, had you burned it from the iso.  Then after "smugging" the CD to produce errors in reading, he then implemented the following process to recover it.  First off was to "read" the iso again to create the restoriation iso (medium.iso), then use the Dvdisaster "fix" function which takes the error correction file and applies fixes to the "damaged" medium.iso succesfully based on the data in the error file.  Clint found this so accurate that he compared the checksum of the "fixed" medium.iso and the original .iso file for the CD and they were identical, an exact replication of the original media!  One the fixed iso is created, then you can use your favorite DVD/DVD burning program and burn a new DVD/CD.  As long as your DVD player/recorder supports it, dvdisaster supports recovery of Blue-Ray and Doublesided media but it does not fix/read commercial DVD's or Blu-Ray disks.

Next up, Clint demonstrated how to boot iso media from the hard disk.  This was also by request of one of the members.

He had two additonal boot media copied ot the /boot folder of his computer.  The Plop Boot Manager and Rescatux livecd repair system.  He showed and explained the /etc/grub.d/40_custom file entries to make these two items bootable from the Hard drive's Grub2 boot manager.

/etc/grub.d/40_custom file:

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
menuentry "Plop Boot Manager" {
    set root='(hd0,1)'
    linux16 /plpbt.bin
}
submenu "Rescatux 0.32" {
    set root='(hd0,1)'
    set isofile=/rescatux-0.32b2.iso
    loopback loop $isofile

menuentry "Rescatux 0.32 - 64-Bit" {
    linux (loop)/live/vmlinuz1 findiso=$isofile boot=live config quiet splash
    initrd (loop)/live/initrd1.img
    }
}

The first menu entry is for Plop, a bin file.  The submenu sets up the Rescatux LiveCD iso file for booting live from the Hard Drive.  Inside the submenu is the actual code that starts the 64 bit version of Rescatux.  Clint explained the importance of the set root parameter which can be hd0,1 or hd0,msdos1, depending on the partioning scheme as determined by grub on installation.  You can check the original /boot/grub2/grub.cfg file menu entries to verify the format used.  Also, he had found that Debian/Ubuntu wants the full root path such as /boot/rescatux-032b2.iso for grub to work where on Fedora, it only uses the / path to the file in the boot folder (or other location).  The cool thing about this is that you make the changes in the 40_custom file, update the grub.cfg with grub2-mkconfig -o /boot/grub2/grub.cfg and reboot to test.  If the is an error, the computer will still boot normally, and you can go back in and fix the 40_custom file; just be sure not to change anything in the opening lines of the file as directed which can be fatal!

Clint booted both Plop and Rescatux for demonstration.  He then spent about 30 minutes going over the repair features found in Rescatux along with using command line to fix problems not directly by Rescatux.  Rescatux available for download from http://www.supergrubdisk.org/, the same place as the supergrub repair disk but Rescatux offers so much more beyond fixing grub problems and file systems, including passwords on both Linux and Windows.There was also an excellent tutorial in Linux Format Magazine Christmas issue 192: http://www.linuxformat.com/archives?issue=192. Rescatux actually boots to a full LXDE desktop and runs as an application front end "gui".  While Rescatux is excellent at doing what it does, some command line knowledge is required to really get under the covers.  The command line tools include fdisk and the logical volume utilities and using fsck at the command line.  Clint also showed how to identity device-mapped (dm) in the /dev/disk/by-id folder and the actual path that you would use with fsck such as /dev/mapper/fedora-home which is in the volume_group-logical_volume format.  He finished up by talking about the purpose of testdisk in recovering lost partitions, and photorec to find deleted files.

Clint finished up his part of the evening by showing Fedora 21 Mate-Compiz that he had installed on his computer and then followed up with a listing of things that he added to the "base installation" based on Things to do after installing Fedora 21- (Post Installation Guide): http://www.attabot.org/featured/after-installing-fedora-21-post-installation/
========================================================
su -c 'yum localinstall --nogpgcheck http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm'

sudo yum install gstreamer1-plugins-good gstreamer1-plugins-good-extras gstreamer1-plugins-ugly gstreamer1-plugins-base gstreamer1-plugsins-base-tools gstreamer1-plugins-bad-freeworld gstreamer1-plugins-bad-free gstreamer1-plugins-bad-free-extra gstreamer1-libav

history:
53  yum install unrar p7zip p7zip-plugins
54  rpm -ivh http://linuxdownload.adobe.com/adobe-release/adobe-release-i386-1.0-1.noarch.rpm
55  rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-adobe-linux
56  yum -y install flash-plugin
57  yum install -y icedtea-web java-openjdk
58  yum install vlc -y
59  yum install audacious gnome-music
60  vim /etc/yum.repos.d/google-chrome.repo
61  yum install google-chrome-stable -y
63  yum -y install inkscape
64  yum grouplist
67  yum groupinstall 'Development Tools'
68  yum -y install dvdisaster
70  yum -y install geany
73  yum groupinstall 'C Development Tools and Libraries'
75  yum groupinstall 'RPM Development Tools'
80  yum -y install python-tools
82  yum groupinstall -y 'Fedora Eclipse'

su -c "curl https://satya164.github.io/fedy/fedy-installer -o fedy-installer && chmod +x fedy-installer && ./fedy-installer"
========================================================

The member Brian H. showed his Installation Script that he uses to do his customizations after a base install.  His script was not complete yet and he said he would make it available when done.  It was very interesting in what he has done so far in using the new version of YUM, called DNF which is the next generation package manager (DNF is an acronym for Dandified) and the different packages that he installs for security purposes.  He showed this on his Laptop using Fedora 21 Workstation with gnome 3. You can download latest version his "Fedora Starter" kit at https://github.com/codemonkeyrawks/Fedora-Starter-Kit, a work in progress.

The meeting wrapped up about 8:30 with some conversations.

Clint asked for suggestions for our April meeting which will be back on Tuesday, April 21st at Taos.