mercury0114's questions

When I type

sudo apt-get install r-base-core

I get the following error

The following packages have unmet dependencies. r-base-core : Depends: libc6 (>= 2.29) but 2.27-3ubuntu1 is to be installed

Now libc6 as far as I understand is an important library which should not be removed.

So how to upgrade from the current version (2.27) to any version >= 2.29?

I connected my TV and laptop using HDMI cable. In the terminal I typed xrandr command. The Ubuntu Desktop GUI appeared on the TV screen.

Based on my understanding, the screen shown on the TV is the second laptops panel. When I go to Settings - Screen Display, I see 2 screens:

1. Built-in Display;

2. Sony 46" (a screen to the right)

If I turn the Sony 46 screen off in the settings, the screen on the TV also turns off. What I want is my TV to show the first Build-in Display screen.

How to do that?

I have installed grub on USB stick. I now want to add "linux.iso" file to the USB, so that on boot I could run linux from USB.

On boot the grub menu opens, but after trying to load external linux, an error message

casper/vmlinuz not found

appears.

I believe it's due to one of the following:

1. .iso file is not in the correct directory. It can be found at:

   /mounted_usb/ubuntu-13.04-desktop-i386.iso
   

2. grub.cfg file is not correctly edited. The cfg file currently looks like this:

   set timeout=10 set default=0
   
   menuentry "Run Ubuntu" {
       loopback loop /ubuntu-13.04-desktop-i386.iso 
       linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=/ubuntu-13.04-desktop-i386.iso splash --
       initrd (loop)/casper/initrd.lz
   }
   

   and is stored at /mounted_usb/boot/grub/grub.cfg

3. Grub was not succesfully installed. I can't locate a file called vmlinuz one the USB. The way I installed GRUB was following this link.

4. The Ubuntu operating system actually needs to be installed on USB. Currently only iso file is present.

Any help? Essentially what I'm struggling is to how create a boot menu on the USB stick? I want to be able flexibly add several Operating Systems to the USB and get them appear on the menu when trying to power on my laptop from USB. The menu itself appears on boot, but the pointer to the operating system is invalid.

I have a directory called my_projects_linux inside the Ubuntu file system, which contains all my work from many years. The directory contains files, subdirectories and so on.

For backup purposes, I occasionally copy this directory and all its contents to external hard drive.

Hence, the contents of my external drive look like:

/mounted_drive/my_projects_linux
/mounted_drive/my_projects_windows  # the same idea to backup Windows work

Hence, what I am looking is a command which:

1. Would work as

   cp /home/my_projects_linux /mounted_drive/my_projects_linux
   

   It should replace old files, subdirectories, files inside subdirectories, etc. in the external disk by the new content from my PC.

2. Be fast. It should only copy modified files or those that have been newly created. Given that the size of my_projects_linux is >50 GB, copying everything takes more than an hour, which is too slow. In reality often only a few MB have changed since last backup, so theoretically a copy can be made much faster.

How to do that?

I googled that cp with the -u flag could possibly match my needs. Would that work (e.g. would it correctly handle subdirectories of subdirectories)?

Also, is storing file system on an external disk an appropriate way of doing a backup, or is there a fancier way? For example, using a cloud? Note that the fancier way should be simple, as otherwise it will not outweigh the ease of executing one shell command.

I would like to install 32bit libraries to run dynamically linked code on Ubuntu 14.04.2 LTS operating system.

Tried two commands, none of them work:

Command no. 1:

sudo apt-get install lib32z1 lib32ncurses5 lib32bz2-1.0

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 lib32bz2-1.0 : PreDepends: libc6-i386 (>= 2.9-18) but it is not going to be installed
 lib32ncurses5 : Depends: lib32tinfo5 (= 5.9+20140118-1ubuntu1) but it is not going to be installed
                 Depends: libc6-i386 (>= 2.4) but it is not going to be installed
 lib32z1 : Depends: libc6-i386 (>= 2.4) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Command no. 2:

sudo apt-get install ia32-libs

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package ia32-libs is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
  lib32z1 lib32ncurses5 lib32bz2-1.0

E: Package 'ia32-libs' has no installation candidate

What is the appropriate command to install 32bit libraries?

Looking through other posts people tell execute the shell commands above to fix the error, but for me the commands do not work.

I've also executed

sudo dpkg --add-architecture i386

since other posts recommended to execute it. It does not seem to help either. When trying to run a file:

./vsim

I get the error

bash: ./vsim: No such file or directory

although the file "vsim" exists:

vsim: ELF 32-bit LSB  executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.4, BuildID[sha1]=31fa816092d910bb32b64ed8ea2a5baa1da6b005, stripped