ubuntu : how to download & install software on USB ?

Answers to your questions

1 . You can open nautilus . This is the GUI (explorer way). Click on Ubuntu's Icon , first in left launcher and write : nautilus

then open nautilus file manager and explore the drives - filesystems - folders - files .. etc.

From command line.
Open a terminal (CTRL+ALT+T) and list all the drives - parititons - filesystem type .. with following command

    sudo fdisk -l

2. With nautilus you can see everything as I wrote in first answer.
From command prompt (CTRL+ALT+T)

    ls -a

will list the contents of the current directory.

3. You can install software in live usb , but it is not persistent. The software and all the changes you have done will be lost in next reboot.
If you want to be able to save software and/or configuration you have done, you must create a Live usb-stick with persistent space.
Read here about this
https://wiki.ubuntu.com/LiveUsbPendrivePersistent

You can install software either from Ubuntu Software Center or from CLI (CTRL+ALT+T).
From CLI (Command Line-Interface) you can use the apt-get.
Example of firefox browser installation

    sudo apt-get install firefox

you have to know the package name , you can find it if you don't know it , but this is not a classroom and I'm not a teacher.
You can search the Web read tutorials ...etc to learn more about the powerful CLI.

Start from Ubuntu Community Documentation page
https://help.ubuntu.com/community/UsingTheTerminal

Regards
 NikTh

Thanks a ton for the Answers

I shall try and revert back

Once again, thanks for making Linux a very interesting system

Regards

//////3. You can install software in live usb , but it is not persistent. The software and all the changes you have done will be lost in next reboot.
If you want to be able to save software and/or configuration you have done, you must create a Live usb-stick with persistent space.
Read here about this
https://wiki.ubuntu.com/LiveUsbPendrivePersistent////////

THANKS for your detailed answer I have one more question...... Hope you can answer

While I boot up with my USB I see the hard drives on my machine , I can see the existing drives and directories etc...

If any software is installed on my hard drives during my Linux session, will they also be erased when I get out of Linux ? Or is this persistence only for USB

TIA

sudo fdisk -l

Will show all hard drives and their respective partitions, is this what you mean?

You cannot install software to another hard drive or/and partition. Linux software (as I know) always installed in /usr/bin/ .

This folder exists in your current Linux operating system (for example, your Live USB-stick). You can install software in other folders but you have to compile it , build it and then you can define another folder. It is a procedure for advanced users.

Regards
 NikTh

The binary you lauch will be in /usr/bin but lots of other files needed to make it run will be in other places. This allows SHARED libs to be used in applications. If one application uses a library and then you install another application using that same library then only one version will be stored on the hard drive and also if both are running then only one version will be stored in RAM and both processes will use it. This allows packages to be smaller and also use fewer resources. Windows would load multiple copys of the same file to RAM and is wasteful (look at svchost.exe for example), it also duplicates effort in the OS to not use this model.

You can mount partitions as folders within the file system (some people like to keep /home and /var on their own partition for example) but the file system will always be the same, the packages will install where they always will. If these happen to be on other partitions then the kernel manages that but you do not get a Windows style installer where you choose the location of the file if you are using deb files, they will simply install.

Thanks to all those who replied

Really appreciated

I couldn't understand actionparsnip 's second para

This is my plan
------------------------------
As of now I shall try to get a 4 gb USB and use 2 gb or so PEresistance, boot from USB and run Ubuntu

What is persistence
-----------------------------------
I tried the link on persistence ...I couldn't gather / undestand the impact of a higher or lower persistence ....for example what are the benefits of a 3 gb persistence over 2 gb persistence ? Is it faster ? Des it store more ? What ?

If I buy a 16 GB flash memory drive, install Ubuntu on that flash drive, and boot from that flash drive can I store files up to 10 GB on that drive or is it limited to the persistence I have set ?

What actually is persistence ?

Is persistence needed when I install on a USB hard drive ..say USB 500 GB hard drive
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Is this perisistance thing valid for install on a USB hard drive only ? Why do I ask ? as an alternative I am thinking of also buying a HDD and running Ubuntu from the HDD on a shared machine ... Can I use the whole 500 gb to store libre office files , photos etc , or ?

Thanks a ton

Le

Read this
http://ubuntuforums.org/showthread.php?t=2076102&p=12317425#post12317425

Regards
 NikTh