p1_p1_p1
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Why are USB flash drives mounted read only?

Sun Apr 15, 2018 3:01 pm

rasp 3 1.2ghz cpu:
i tried also everything, and everytime i plug usb flash i must manualy remount that for RW,
doesnt matter if it is ntfs, fat, fat32 ....

is there any WORKING solution so EVERYBODY i plug ANY FLASH in USB so it is mounted as RW?


tried also http://raspi.tv/2012/how-to-mount-and-u ... spberry-pi

tried editin fstab with ntfs-g3,vfat option and ... nothing works :roll: :lol: so i tried same command on debian live on pc and works, so it must be some mess with the Raspberry

Ernst
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Re: USB Hard Drive Permissions

Sun Apr 15, 2018 4:00 pm

You may have more success if you look at the date of the posts, ignore the contents referring to "old" versions, and instead open new thread where you provide description of your configuration and your problem.
My first computer was an ICT1500, my first "personal" computer was the Sinclair MK14

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mahjongg
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Re: Why are USB flash drives mounted read only?

Sun Apr 15, 2018 4:47 pm

Split off from ancient obsolete thread (and locked it) and renamed the subject to the real question.
Delete some ranting, please keep your cool...

p1_p1_p1
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Re: Why are USB flash drives mounted read only?

Sun Apr 15, 2018 8:25 pm

looks like everything in raspberrry is obsolete ...

n67
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Re: Why are USB flash drives mounted read only?

Sun Apr 15, 2018 8:39 pm

p1_p1_p1 wrote:
Sun Apr 15, 2018 8:25 pm
looks like everything in raspberrry is obsolete ...
I suppose we could start with:

What makes you think it is mounted read-only?

And go from there...

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thagrol
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Re: Why are USB flash drives mounted read only?

Mon Apr 16, 2018 12:01 pm

With the drive mounted, run

Code: Select all

mount
and look for your flash drive in the output.That'll tell you what mount options have actually been used and whether the drive has been mounted read only (ro) or not.

Outside of the desktop's automounter, mounts are normally performed by root and default permissions only allow root to write to the mounted drive.

The default driver for ntfs only provides read access, it does not provide write access. If your drive is NTFS, try installing ntfs-3g:

Code: Select all

sudo apt install ntfs-3g
No version of fat supports linux/raspbian file ownership and permissions so these are faked by the driver. Try adding "umask=0000" to the mount options to override the defaults and give full permissions to everyone. This may work for ntfs too. This approach isn't secure but is easy.

Take a look at the man page for mount for more detailed information:

Code: Select all

man mount
Note to self: don't feed the trolls

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thagrol
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Re: Why are USB flash drives mounted read only?

Mon Apr 16, 2018 12:06 pm

Oh, it would help if you posted the actual commands and fstab entries you're using both on debian and raspbian. Cut and paste please not retyped.
Note to self: don't feed the trolls

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mahjongg
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Re: Why are USB flash drives mounted read only?

Mon Apr 16, 2018 12:10 pm

He won't as he was banned for excessive concern trolling.

If I can summarize the answers given:

If you mount an external medium from the GUI, it will be mounted Read-Write, unless its contents are formatted NTFS, in which case you need to install a new (experimental) NTFS driver that supports writing (because Microsoft has refused to publish details about NTFS, and so the NTFS driver had to be reverse-engineered which is safer if it can only read, not write).

If you manually mount from the command line you have to explicitly specify you want write rights, that is how Linux works.

please correct me if I'm wrong.

n67
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Re: Why are USB flash drives mounted read only?

Mon Apr 16, 2018 1:58 pm

(No big deal and just in the FWIW category)

It looks like NTFS-3G is about 12 years old.

According to:

https://www.tuxera.com/community/release-history/


2006.07.14 — Release Notes
First NTFS-3G BETA release.

Anyway, I think most people consider it reasonably stable and reliable - not "experimental".

Of course, there's always a risk (and I mean that term in ways other than the obvious one) involved when using non-native code to access a filesystem (I.e., Linux accessing Windows filesystems or the reverse). But if you can live with that, you should be OK.

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mahjongg
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Re: Why are USB flash drives mounted read only?

Mon Apr 16, 2018 2:09 pm

Yeah, I agree, ntfs-3g is well beyond the beta stage, its just that formally its not 100% complete, (it can't be because actual specifications are not available) and so its theoretically possible that some nasty feature/bug/strangeness of NTFS is not properly implemented.
Because of that distributors of Linux are scared to formally accept responsibility for the use of ntfs-3g for writing to an NTFS file system, fearing that if anything goes wrong they will be held responsible, therefore they shift responsibility for using ntfs-3g to the user.
Thanks Microsoft :evil:

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