Learning Linux : multiple roots ?

[FanOfLinux]

I am not quite sure, what you mean.
All what is inside sda7 will appear in the mount folder

Here are 3 pictorial descriptions.
I create sda7_dir on attached sda6;

Selection_001.png

Now I added mount sda7 at mount point sda7_dir.
Assume sda7 is another ext4 filesystem with a complete Linux OS.
Which of following result will I get?
a)

Selection_006.png

b)

Selection_005.png

As for:

You have in a VM 2 possibilities:

If you can point me to where I can read up on how to do these VM possibilities,
I would try it later...

Thanks.

[Cosmo.]

To the first question: None of both.

If you mount the partition sda7 into the folder sda7_dir, you see by opening sda7_dir the content of the partition sda7 (that what you showed in the pictures in the bottom most row). This is, what I wrote here in the last sentence.

To VB:
VB comes with a detailed help file, where many questions are answered.
Anyway: My first given possibility has in fact nothing to do with VB. You start the live system inside the new VM and create the partitions before installing the OS.
Regarding the second possibility you might refer to chapter 3.6 of the help file.

[wong]

https://vimeo.com/153261792

[kcoady]

Hi. I'm new to Linux, but I ran a Unix system thirty years ago. To answer your initial question about why there are so many roots --

Back in the day, there was no /root directory in many Unix versions. root was the user whose home directory was /. That was OK because most users, including root, didn't have nearly so many hidden program startup files as you see now.

On our system root had a .profile and a couple of .thisprogramrc and .thatprogramrc. files (the rc stands for runtime control: it's like an ini file: it holds some initial program settings.) It wasn't confusing even if you listed the root directory and showed hidden files because there weren't that many.

Today there are usually many more startup files and if you put them in / it'd make ls -la / (a directory listing showing hidden files) pretty cluttered. So it became more practical to started giving root its own home directory.

[FanOfLinux]

Wong:

Thanks for the video.
Nice work. Bigger fonts would be nicer...
What tool did you use for recording?

How did you create the sda3 partition inside Virtual Box (VB)?
Then it looks like you install linux on sda3.
If you got time, a video on creating multiple partitions from inside Vb would be nice for newbies like me.

On the later part of video, related to media/ :
a) it looks like you plug in a USB drive.
Did VB automatically assign it to sda3?

The complete set of linux directories in the usb drive, how did you create that?
Thanks.

[wong]

Nice work. Bigger fonts would be nicer...

Have you tried Vimeo in fullscreen mode?

What tool did you use for recording?

VirtualBox has a built in screengrab/recorder, there's a little icon on the bottom right of the VM. I had to change the recorder resolution setting to get a fullscreen recording.

How did you create the sda3 partition inside Virtual Box (VB)?

Using gparted on the Linux Mint Live iso.

Then it looks like you install linux on sda3.

Before recording I installed Linux Mint to sda1, shrunk sda1, created sda3 and installed linux mint on there too. All you see in the video is mounting and unmounting, no installing linux or accessing other drives.

On the later part of video, related to media/ :
a) it looks like you plug in a USB drive.
Did VB automatically assign it to sda3?

In the first part I use the terminal to manually mount, and unmount, sda3 to sda3_dir...to match your earlier idea of sda7_dir under /
In the latter part I use my file manager, caja?, to automatically mount sda3, it just calls it '9.7GB Volume' or something and instead of mounting it to /sda3_dir it likes to mount it to /media/wong/uuid-numbers-and-letters/

[FanOfLinux]

Wong:

Thanks.

I will try it soon.

About screen resolution on VB.
Linux Mint display nicely on VB. it scales to cover entire VB area.
Now,the VB is inside Linux Mint 17.1.
When I have Ubuntu server inside VB, the screen for the server is VERY tiny.
I look online for help, but those suggestions did not work.
But screen for VB will cover my entire display regardless of Ubuntu server display size..
I suspect I may have same problem with CentOS or Red Hat server, but have not tried them yet.

Do you have this problem, assuming you use a server on VB?
.

[wong]

Ubuntu server is working here at 1920x952 which is plenty for a server. Maybe try the following on the Ubuntu guest and reboot;

Code: Select all

sudo apt-get install virtualbox-guest-X11
sudo apt-get install virtualbox-dkms

If not try installing other stuff with 'virtualbox-guest' in the title.

[FanOfLinux]

Hello Wong:

i am now going to install a new virtual box.
As I mentioned before, my problem is the small display area of the VM.
The VM screen stay small even after I maximize Virtual box window.
So I decide to remove VB and start over.
I maybe using the VB downloaded (V 5) from Oracle's site.

You mention this to help solve my small VM screen problem:

sudo apt-get install virtualbox-guest-X11
sudo apt-get install virtualbox-dkms

What do they do?
Do I still have to install VB after the above install?

I look into Software Manager and search for Virtual Box.
I found 4 listed:
-virtualBox-nonfree
-virtualboxx86 virtualization binaries
-virtualbox 4.3
-virtualbox-qt

What are the differences?
Which to use?

Thank you.

[wong]

VirtualBox from the Linux Mint repos should do just fine.

I don't have access to a Mint machine at the moment but once you have a virtual machine up and running installing the guest additions on the guest operating system should allow better integration with the host OS and enable more control over resolution, shared clipboard, shared folders and whatnot. You can either install them directly on the guest or install on the host and load the guest-iso from the devices devices tab on Virtualbox when the virtual machine is up and running.

Another factor could be the video/gpu ram, you can check the machine settings in Virtualbox settings under the display tab. I think the default is pretty low.

I'm not sure about the differences between those specific packages but Virtualbox comes in a command line only interface and a graphical use interface(Qt). The other distinction is in licensing, VirtualBox is available under the GPL but other features are non-free.

[FanOfLinux]

I don't have access to a Mint machine at the moment but once you have a virtual machine up and running installing the guest additions on the guest operating system should allow better integration with the host OS and enable more control over resolution, shared clipboard, shared folders and whatnot. You can either install them directly on the guest or install on the host and load the guest-iso from the devices devices tab on Virtualbox when the virtual machine is up and running.

OK, I am missing something here.
I am not sure what you mean by the above underlined statement,particularly what is meant by
"... installing the guest additions on the guest operating system..."
What is guest additions and what is guest operating system?

Here is what I did:
I installed this VB via download:
virtualbox-5.0_5.0.16-105871~Ubuntu~trusty_amd64.deb

Then I installed this (which I call the CentOS VM) via a wizard interface by clicking the "New" button:
CentOS-7-x86_64-DVD-1503-01.iso

There is no menu of anything like "Install guest addition...." to click....

So what did I missed?

[wong]

By guest/host I mean:

Host - the operating system you have installed directly on your PC, your main OS.

Guest - an operating system running as a Virtual Machine within VirtualBox.

Youtube vid of installing guest additions using VirtualBox:
https://www.youtube.com/watch?v=DoG0NA_OzsI

You can also install guest additions using the native package manager: yum/apt-get/pacman etc.

[FanOfLinux]

Just wondering,,,, it that you on the video?

Youtube vid of installing guest additions using VirtualBox:
https://www.youtube.com/watch?v=DoG0NA_OzsI

I looked at the video demo.
His VB may not be same as mine.
After ubuntu VM is up, his menu list are: "Machine View Devices Help"
While mine are: "File Machine View Input Devices Help"

It looks like I do not have the same VB since the UX is not the same as the youtube demo.
May be this is a minor issue....
========================
if I am not mistaken:
Here is what the youtube video shows:
1) He installed a VB on his desktop.
2) Then run the VB and install Ubuntu Gnome inside theVB.
3) So now he has Ubuntu Virtual Machine (VM) running inside VB and then from
inside the VB, he clicks VB's menu item "Devices" > "Insert Guest Additions CD Image.... "
4) Then he is prompted to clicks download to install the guest addition.

But I have this error message after I clicked "Insert Guest Additions CD Image.... ":

Could not mount the media/drive
'/usr/share/virtualbox/VBoxGuestAdditions.iso'
(VERR_PDM_MEDIA_LOCKED).

Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
ConsoleWrap
Interface:
IConsole {872da645-4a9b-1727-bee2-5585105b9eed}
Callee:
IMachine {f30138d4-e5ea-4b3a-8858-a059de4c93fd}

It seems like the demos shows the VB know where to find or download the guest addition.
But my (latest) VB5.0 is not able to do so.

How do I get VB to find the guest addition or how do I download the guest addition iso into the correct place for VB to install as guest addition iso?

As a side topic, can we run a VM with a different guest addition, an example would be to run a lightweight Linux Mint VM with a CentOS guest addition ?

Addendum:
I found these on my Linux Mint host (not inside the VM):
/usr/share/virtualbox $ ls -al
total 59912
drwxr-xr-x 5 root root 4096 Mar 11 14:40 .
drwxr-xr-x 332 root root 12288 Mar 11 11:17 ..
drwxr-xr-x 2 root root 4096 Mar 11 14:40 nls
drwxr-xr-x 2 root root 4096 Mar 11 14:40 rdesktop-vrdp-keymaps
-rw-r--r-- 1 root root 1236823 Mar 4 10:22 rdesktop-vrdp.tar.gz
drwxr-xr-x 3 root root 4096 Mar 11 14:40 src
-rwxr-xr-x 1 root root 1505 Jun 9 2015 VBoxCreateUSBNode.sh
-rw-r--r-- 1 root root 60063744 Mar 4 10:25 VBoxGuestAdditions.iso
-rwxr-xr-x 1 root root 4161 Jun 9 2015 VBoxSysInfo.sh
-rwxr-xr-x 1 root root 4350 Oct 11 2014 x11config.pl

/usr/share/virtualbox $ file VBoxGuestAdditions.iso
VBoxGuestAdditions.iso: # ISO 9660 CD-ROM filesystem data 'VBOXADDITIONS_5.0.16_105871'
----------------------------------
So I am perplexed ...ouch!
Thank you.

[wong]

No, not my video. You are not mistaken in your estimation of the video.

I'm running VirtualBox 5.0.16-1 at the moment but on an Arch host. I have no experience with CentOS.

I would guess the Ubuntu VM played nicely with VirtualBox as you grabbed a version of Ubuntu tailor made for Virtualbox. With Cent OS you may have installed a system that is not aimed at producing high resolution on a virtual machine out of the box.

The Cent OS wiki advises the installation of dkms, development environment & kernel sources before attempting to install guest additions, it also gives a gui and more manual method to install the guest additions.

I had a few days this week I couldn't start my vm's due to errors with kernel modules and headers I can't quite grasp but things are up and running again.

---------

Loaded up a cent os vm out of curiosity. Minimal install console is 640x480 or thereabouts, gnome is 1024x768 here. Looks like I'd need to install dkms from the epel repo, which I'd need to add via yum.conf to get started on the road to 1080p but I have a game of Total War that needs tending and my need to learn yum is not strong.

Hope this helps, might be worth starting a fresh topic to attract the attention of people using virtualbox with little interest in multiple roots.

[FanOfLinux]

Wong:

Thanks.
One more question about resizing partition.
Your wrote:

I asked:
How did you create the sda3 partition inside Virtual Box (VB)?
You wrote:
Using gparted on the Linux Mint Live iso.

I just want to make sure I understand what you did here.
To run the Linux Mint Live iso and use its gparted for a VM partition shrinking, you must be inside a running Linux VM, say a Linux Mint VM, and then you run the Linux Mint iso from inside the VM. Correct?

[wong]

No.

You boot into a live iso as you would on real hardware. Likely similar to powering off windows, booting into the Mint live cd which will shrink the windows partition and install Mint on the free space.

- Power off mint VM
- Virtualbox Settings for Mint VM > Storage > Controller: IDE
- Click cd/dvd icon with + > choose disk > navigate to live iso
- power on VM and you should have booted into the live image
- proceed to fix/destroy your existing install and play around with partitions