SC430nut
Posts: 2
Joined: Thu Aug 08, 2019 7:19 pm

Do installed programs get written to the uSD card?

Thu Aug 08, 2019 7:45 pm

Greetings All,

I am a true newbie as it applies to Pi and Raspbian, but have some understanding of systems and software due to having worked in tech since the early '70s.

My question is: if I install a program on my Rpi 3B+ using a USB thumb drive, will the executable code be written/appended to the os image on the uSD card?

If so, does that mean that I need to copy the entire uSD card to create a backup with dd?

Thanks for helping me with the most very basics.

Cheers to you.

W. H. Heydt
Posts: 11695
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Do installed programs get written to the uSD card?

Fri Aug 09, 2019 4:59 am

The uSD card in a Pi is analogous to the HDD (or SSD) in a PC. There is no generally writable non-volatile storage on a Pi. (There are two exceptions. Prior to the Pi4B, there is a minimal amount of one time programmable--OTP--storage, where single bits might be set, but can then never be reset. On the Pi4B, there is a 512KB EEPROM that holds such firmware as the Pi has. The EEPROM can be re-written to get updates.)

Whether or not programs on a USB stick are written to the uSD card depends on what you do. If it's a package with an installation program, then it probably does get written to the uSD filesystem. If what is on the USB stick is just executables and you don't mover or copy them somewhere else, then no, they won't be written to the uSD card.

Linux (like unix before it) allows far more user/sysadmin control than popular, mass market, OSes. The flip side of this is that you are allowed to make mistakes that will trash the whole system without warning. Think of it as a learning experience....which is what the Pi is all about.

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HawaiianPi
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Location: Aloha, Oregon USA

Re: Do installed programs get written to the uSD card?

Fri Aug 09, 2019 5:15 am

SC430nut wrote:
Thu Aug 08, 2019 7:45 pm
My question is: if I install a program on my Rpi 3B+ using a USB thumb drive, will the executable code be written/appended to the os image on the uSD card?
That depends on what you re using the USB thumb drive for. It's possible to boot and run a 3B(+) from a USB drive with no SD card at all, or you can have /boot on the SD card and / (the root filesystem) on USB. If your Pi is running entirely from the SD card, and the USB thumb drive is just for storage, then yes, software that is installed in the typical way will be added to the OS on the SD card.

However, installing software from a USB drive is not the way it's typically done, so you will have to clarify that point for more information (software for Linux is normally installed from online repositories, not by downloading software installers like on Windows).

If so, does that mean that I need to copy the entire uSD card to create a backup with dd?
Using dd is a very poor way to backup your system. Look for some tutorials on making Linux backups for more reliable solutions.
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?

dominic03
Posts: 91
Joined: Fri Dec 21, 2018 1:50 am

Re: Do installed programs get written to the uSD card?

Fri Aug 09, 2019 11:33 am

SC430nut wrote:
Thu Aug 08, 2019 7:45 pm
Greetings All,

I am a true newbie as it applies to Pi and Raspbian, but have some understanding of systems and software due to having worked in tech since the early '70s.

My question is: if I install a program on my Rpi 3B+ using a USB thumb drive, will the executable code be written/appended to the os image on the uSD card?

If so, does that mean that I need to copy the entire uSD card to create a backup with dd?

Thanks for helping me with the most very basics.

Cheers to you.
If you want to make backups, I suggest deja-dup (GNOME backup tool)

Code: Select all

sudo apt install deja-dup
Raspberry Pi 4B running Raspbian Buster v3.1 (via PINN)
Kingston 32 GB C10 (U1) microSD
Sceptre E225W 22" 75hz 1080p monitor
Flash drive for backups and swap
-or-
pi-top 3 running Raspbian with drivers and pi-topHUB 2.0 / 16GB SanDisk C10 microSD

Andyroo

Re: Do installed programs get written to the uSD card?

Fri Aug 09, 2019 2:41 pm

If you have the Raspbian GUI installed then the simplest way is to use the provided SD Copy tool.

This lets you copy the current SD Card to one connected via USB and copes with different sized cards.

Edit: Forgot - if you do not have the GUI then look at https://github.com/billw2/rpi-clone

SC430nut
Posts: 2
Joined: Thu Aug 08, 2019 7:19 pm

Re: Do installed programs get written to the uSD card?

Fri Aug 09, 2019 4:31 pm

Thanks very much for the explanations - I also located the RPi manual, so I hope to post more interesting questions in the future.
Cheers to all!

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