[SOLVED] How to make USB stick readonly

andrewysk · 06-02-2021, 12:03 PM

I got a usb stick preinstalled with win os image that i keep. I made a wrong move and destroyed the usb stick, it is no longer able to install win7.

Hence i would like to make it readonly so that that won't happen in future.
I know how to make it in windows os.. but i have not find way to do it in linux.

After much searching around, only found this.
Is this the method ? Is there any other method ?

Code:

$ sudo hdparm -r1 /dev/sdc

Thanks

computersavvy · 06-02-2021, 12:07 PM

A quick google search for your question turns up a LOT of responses.

andrewysk · 06-02-2021, 05:18 PM

Quote:

Originally Posted by computersavvy

A quick google search for your question turns up a LOT of responses.

Really ? I must have entered wrong search key.. because i have being searching multiple times.
The result was always in Windows os method. = diskpart method
and fix usb readonly problem (instead of making it readonly),
never one that uses linux to make usbstick readonly.

The

Code:

$sudo hdparm -r1 /dev/sdc

method was the only one i got from digging around in linux forum, even then, i think there is other method, something like attribute change, but i am not sure if it is suitable .

Can you give me the keyword that you search which you said got plenty of result ? I often don't know what keyword to search, hence poor usable result

andrewysk · 06-02-2021, 05:43 PM

After some more reading, i think the conclusion is, unless it is a sdcard with lock switch, there is no way to make usbstick readonly, because any partitioning or formating will destroy the "readonly" data in usbstick.

jefro · 06-02-2021, 07:41 PM

I'd try testdisk on it to see if you can recover the data.

sundialsvcs · 06-02-2021, 08:00 PM

I have always wondered why USB sticks don't have a hardware "write protect" switch. I cheerfully would pay another 3¢ for such a very-useful thing ...

Hell, floppy disks always had one ...

However, so far as I know, unless you are using a stick that does have one, there's no way to actually prevent your data from being overwritten. (Which, to me, is absolutely stupid ...)

syg00 · 06-02-2021, 09:13 PM

They used to exist, I had at least one. A quick search turned up a 16G USB3 with a switch on Amazon, so they are still being offered. If your data are that valuable, put up with the extra cost.

computersavvy · 06-02-2021, 09:20 PM

The full size SD cards had the write protect switch, and as has already been stated some USB sticks do.

My search was for "how to write protect a flash drive" which turned up about 46 million results. I did not of course dig any deeper, although the first several had interesting summaries.

andrewysk · 06-03-2021, 01:59 AM

Quote:

Originally Posted by sundialsvcs

I have always wondered why USB sticks don't have a hardware "write protect" switch. I cheerfully would pay another 3¢ for such a very-useful thing ...

Same feeling here too.

This one got a lock switch. Cost 32 euro instead of normal 7 euro. crazy

Code:

amazon
Kanguru FlashBlu30 USB-Speicherstick, USB 3.0, 16 GB, Blau
Marke: Kanguru
Jetzt: 	32,08 €

andrewysk · 06-03-2021, 02:07 AM

Quote:

Originally Posted by computersavvy

The full size SD cards had the write protect switch, and as has already been stated some USB sticks do.

My search was for "how to write protect a flash drive" which turned up about 46 million results. I did not of course dig any deeper, although the first several had interesting summaries.

I checked out your search on google.. the top 2 results are all in windows os method. The next result is "how to format write protected usb stick" or similar stuff.. lol.. Not what i am looking for.

Anyway, Since i know the TRUTH about write protection.. i won't bother to proceed anymore.
Thanks all for info.
CLose thread

cynwulf · 06-03-2021, 02:15 AM

You want to ensure that device is always mounted read only. There are a few means of achieving this, dependent on how the device is mounted, but in terms of accidentally wrecking it with dd, the only precaution against that is to take more care.

pan64 · 06-03-2021, 02:28 AM

Quote:

Originally Posted by andrewysk

Anyway, Since i know the TRUTH about write protection.. i won't bother to proceed anymore.

No, you still don't know. You can mount any usb in read only mode - if you wish. There are at least two ways to do that:

1. configure your system to ensure device is automatically mounted in read only mode (post above)
2. write a simple script to lock/unlock that [any?] device any time you wish. That means you can change the mount from read/write to readonly mode (or back) with a click.

andrewysk · 06-03-2021, 02:47 AM

Quote:

Originally Posted by jefro

I'd try testdisk on it to see if you can recover the data.

Thank you for your suggestion. I regret for not thinking of "recovering data" this path.. I have tried to locate another window image and already dd it onto the usbstick .. now need to know if this image is safe to use or not.

Weird: Why is it read-only when i just dd into it ? How to know what protection mechanism is used ?

Code:

$ sudo mount -o rw /dev/sdd /run/media/usbstick/
mount: /run/media/usbstick: WARNING: source write-protected, mounted read-only.

I want to umount it first and remount it to another folder, but i keep getting this: Bash crashed. what does that mean ? is it terminal is accessing the device ?
How to umount it in this case ?

Code:

$ sudo umount /dev/sdd
umount: /run/media/usbstick: target is busy.

$ fuser -mki /dev/sdd
/dev/sdd:            140805c
Kill process 140805 ? (y/N) y


Warning: Program '/bin/bash' crashed.

pan64 · 06-03-2021, 02:52 AM

fuser -k will kill the process which uses the given resource. That's why it is crashed.
Bash is not a terminal, but a shell, which is usually running inside terminal windows, but can be executed independently from any terminal.

sundialsvcs · 06-03-2021, 09:00 AM

It just seems weird to me that every USB stick does not have these, "quite routinely." Were designers really trying that hard to save a couple of pennies?