Use Pi OS to access sd card reader and config.txt on another Pi OS sd card

[raspnoobfan]

I wanted to change the config.txt on a backup Pi OS sd card using a usb card reader and it will not work on the raspberry. I can access this on a windows PC or even a rock64 running armbian. When I try it in Pi OS it does not mount anything or show up in file manager. It gives me the warning when I disconnect saying to safely eject to prevent data corruption yet does not give me the eject button or the option.

Is this a safety procedure that Pi OS has built in?
How do you easily override this?

[FTrevorGowen]

I wanted to change the config.txt on a backup Pi OS sd card using a usb card reader and it will not work on the raspberry. I can access this on a windows PC or even a rock64 running armbian. When I try it in Pi OS it does not mount anything or show up in file manager. It gives me the warning when I disconnect saying to safely eject to prevent data corruption yet does not give me the eject button or the option.

Is this a safety procedure that Pi OS has built in?
How do you easily override this?

Have you/Is "automount" disabled within the file manager's options - somewhat like this, a little old, example for Jessie:
https://www.cpmspectrepi.uk/raspberry_p ... Auto-mount ?
I would expect a written uSD card in a USB-based card reader (perhaps after an unplug/re-plug to trigger the auto-mount) to appear with partitions mounted at /media/pi/boot and /media/pi/rootfs like the penultimate (11th.) screenshot shown in my "cloning Buster" webpage: https://www.cpmspectrepi.uk/raspberry_p ... OnP4B.html
Trev.

[raspnoobfan]

Most of this section was written in the early days of Raspbian Wheezy, pre-B+ Pi's, when more than one USB stick required the use of a (powered) external hub

DANG that is old school! My first Pi was a 3 B+

[FTrevorGowen]

Most of this section was written in the early days of Raspbian Wheezy, pre-B+ Pi's, when more than one USB stick required the use of a (powered) external hub

DANG that is old school! My first Pi was a 3 B+

My first Pi is one of the "second batch" which, IIRC, I received circa August/September 2012 - early pics. here: https://www.cpmspectrepi.uk/raspberry_p ... 29_Piccies_...
but, relatively recently tested with Buster here: https://www.cpmspectrepi.uk/raspberry_p ... cTest.html
So that's almost, but not quite, "ancient school" (there's no 'photo's of my earliest tests using composite video into a 30" JVC "flat screen" CRT TV )
Trev.

[HawaiianPi]

As FTrevorGowen said, a PiOS card in a card reader should auto-mount upon insertion. If it doesn't, then either something is wrong with the card or the card reader. Try installing Gparted (sudo apt install gparted) and see if that can detect the card.

If your other Pi is a 3B with the USB boot OTP bit set, or a 3B+ (which supports USB boot out of the box) you could try booting from a USB flash drive and interring the card you want to edit into the Pi's card reader. Could also do that with a 4B and the new bootloader.

My first Pi is one of the "second batch" ...

My first one was also a revision 2 model B with 512MB of RAM. Still have that one around somewhere. I skipped the Pi2 (although my GF has a 2Bv1.1), but couldn't resist the Pi 3B when it was launched and ended up with quite a few of those. Most were replaced with 3B+ models, but I still have one original 3B. Still have most of my 3B+ models. Never got any of the A/A+ models, but I have all 3 revisions of the Pi Zero.

Now I also have a 4B2 and 4B4, which are both version 1.1 (purchased shortly after launch), and I'm sure more will come in time (would love to get an 8GB), but finances are tight right now.

[raspnoobfan]

Have you/Is "automount" disabled within the file manager's options

Any regular usb flash drive mounts right away (sorry I did not answer that first).

Gparted detects the drive, the fat32 and ext4 partition, I just cannot mount them for some reason in gparted or Pi OS.
Again I thought this was a safety feature but what do I know.

[raspnoobfan]

I do not know what I was doing wrong. I first tried cat /etc/fstab/ and it said I did not have permissions. I entered sudo su and did the exact command and the terminal interface keptspitting out gibberish. This problem OS was on a 16 gb sd card, I did not think that matters. I thought I updated all the packages doing upgrade and update

Anyways I burned a new image on a 64 Gb micro sd card and it recoqnized immediately, both partitions. I do not know what caused that but I think the problem OS on the 16 Gb card may not have updated properly by me.

Thank you so much for the help fellas. I would help people on the forums but I do not know squat about raspberry that I do not learn here. Thanks Again.

[W. H. Heydt]

My first Pi is one of the "second batch" which, IIRC, I received circa August/September 2012 - early pics. here: https://www.cpmspectrepi.uk/raspberry_p ... 29_Piccies_...

My first two Pis have 256MB of RAM and 140mA polyfuses for each of the two USB ports.

[FTrevorGowen]

My first Pi is one of the "second batch" which, IIRC, I received circa August/September 2012 - early pics. here: https://www.cpmspectrepi.uk/raspberry_p ... 29_Piccies_...

My first two Pis have 256MB of RAM and 140mA polyfuses for each of the two USB ports.

As did (does) "raspiblack". "Pi #2", raspiblue is a early B2 with 512Mb, better pics. here: https://www.cpmspectrepi.uk/raspberry_p ... uePis.html
Trev.

[pfletch101]

I wanted to change the config.txt on a backup Pi OS sd card using a usb card reader and it will not work on the raspberry. I can access this on a windows PC or even a rock64 running armbian. When I try it in Pi OS it does not mount anything or show up in file manager. It gives me the warning when I disconnect saying to safely eject to prevent data corruption yet does not give me the eject button or the option.

Is this a safety procedure that Pi OS has built in?
How do you easily override this?

Coming rather late to the thread: I think that your problem may well have been precisely that this was a 'backup' SD card. If this was a backup of the boot SD card on the system on which you were trying to read it, made by means of the SD Card copier, and you did not specify 'New Partition UUIDs' when you made it, you would not be able to mount it. AFAIK, the OS will not mount a device that has the same Partition UUID as an existing mounted device. If you want to be able to access a backup copy of the system of which it is a backup, you need to tick the 'New Partition UUIDs' box when you create it.