Cannot change file permissions

[Kronix]

I know how to use a Raspberry Pi, that's not the problem. I am trying to change file perms to execute compiled C code and even after using `sudo chmod -x |filenamehere|`, it still says permissions are denied. I am the only user and superuser on this system (Raspberry Pi 3 Model B) so I don't get it. Also, in pcmanfm, the default file manager, when I try to change the permissions, it does a reload of the folder page and it resets to default. I can provide screen proof, but the video may be slow.

Edit: Talking about +x in the chmod command, not -x

[klricks]

To change permissions with File Manager (pcmanfm), open a terminal and use sudo.

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sudo pcmanfm

[thagrol]

even after using `sudo chmod -x |filenamehere|`, it still says permissions are denied.

Was there a typo in that? It's "+" to add a permission "-" to remove it. sudo chmod -x somefile will remove execute permission not add it.

Assuming, of course, the file is on a file system that supports Linux style owner, group, and permissions.

[Kronix]

Right, yes, that was a typo. Just used to - arguments.

[Kronix]

To change permissions with File Manager (pcmanfm), open a terminal and use sudo.

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sudo pcmanfm

Even this doesn't work! It doesn't do the little refresh, however, even though the perms aren't changing.

[thagrol]

Three further things to check:

1. Is the partition containing the file using a file system that doesn't natively support permissions (FAT, NTFS, a remote SMB share, etc.)
2. Has it been mounted read only?
3. Has it been mounted with the noexec option?

[Kronix]

I have checked and it says it's VFAT. (but why tho) It isn't read only, as I put the code on there in the first place, but it may be a file system that doesn't allow perms.

[hortimech]

Where have you saved the file ? On my rpi's vfat is only used for /boot and vfat isn't a Unix filesystem, so Unix filesystem tools do not work.

[Kronix]

Well, the file is stored on my 16gb USB drive formatted with vfat in ./Progamming/C/

How can I format the drive?

Edit: Forgot about Imager

[Kronix]

So I reformatted the drive using Imager (FAT32) after moving my files from it to a safe folder. When I move them back, an error occurs and there are a few files left in the backup folder. Then I find that the drive can no longer be accessed and so I have lost everything (except for a few Spotify application files because I wanted portable Spotify). How is this happening? And why is Linux weird?

[hortimech]

It sounds like you used another non Unix filesystem 'fat32', you should have used a Unix filesystem such as ext4.
Why your files have disappeared, who knows, we were not there when you did the copy (you did do a copy ?).
Linux isn't weird, it is just different from Windows.

[klricks]

So I reformatted the drive using Imager (FAT32) after moving my files from it to a safe folder. When I move them back, an error occurs and there are a few files left in the backup folder. Then I find that the drive can no longer be accessed and so I have lost everything (except for a few Spotify application files because I wanted portable Spotify). How is this happening? And why is Linux weird?

Do any of the filenames have mixed CaSe?
In Linux filesystems, file.txt and FILE.txt are 2 different files.
In Windows filesystems (FAT32 etc), file.txt and FILE.txt are treated as the same file. This can lead to loss of files when copying BTDT.

Also I don't think pcmanfm supports auto refresh. You may need to press F5 to refresh.

[Kronix]

Well, I don't think any of the files have mixed case or the same name, but even if it did, it doesn't explain why I can't access the drive. When I use lsusb the drive is there, but anywhere else it's not accessable.

[thagrol]

So I reformatted the drive using Imager (FAT32) after moving my files from it to a safe folder. When I move them back, an error occurs and there are a few files left in the backup folder. Then I find that the drive can no longer be accessed and so I have lost everything (except for a few Spotify application files because I wanted portable Spotify). How is this happening? And why is Linux weird?

FAT32 (and all other varients), exFAT, NTFS and other non linux native filesystems have no support for owner, group, and permissions. What you see is set in the driver, the same for all files, and cannot be changed with chmod or chown. FAT/exFAT don't even have a concept of owner or group and the only permissions it supports are "read only" and "archive".

You have two choices:

1. Reformat to ext4 or another Linux native file system
2. Mount it with different options so everything on it has the execute bit set.

For the latter see the output from

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man mount

and the FAT related sections of Using fstab A Beginner's Guide (full disclosure: I wrote that guide)

[Kronix]

But how can I detect the USB drive, let alone mount it, if I don't know how? I've tried websites, forums, even AI. No luck. It even isn't showing in Imager! I've tried many things except for physical inspection/potentially reparation, which I don't want to do as i don't have the resources.
The only thing that allows me to know the USB is still working to an extent is that it shows up on

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sudo dmesg

without any errors:

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[ 4677.662375] usb 1-1.4: new high-speed USB device number 8 using dwc_otg
[ 4677.793225] usb 1-1.4: New USB device found, idVendor=1e3d, idProduct=198a, bcdDevice= 1.00
[ 4677.793277] usb 1-1.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 4677.794312] usb-storage 1-1.4:1.0: USB Mass Storage device detected
[ 4677.795440] scsi host0: usb-storage 1-1.4:1.0
[ 4678.833059] scsi 0:0:0:0: Direct-Access     ChipsBnk Flash Disk       5.00 PQ: 0 ANSI: 2
[ 4678.834196] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 4678.835154] sd 0:0:0:0: [sda] Media removed, stopped polling
[ 4678.836556] sd 0:0:0:0: [sda] Attached SCSI removable disk

Edit: At least I don't think...

[thagrol]

So the OS is recognising your USB drive but may or may not be mounting the partition and you don't know where if it is.

It would appear from your references to pcmanfm you're working in the desktop even if not booting directly to it.

The default behaviour under the RPiOS desktop is to mount all partitions on a drive when it is plugged in unless you have am entry in /etc/fstab for a particular partition. Those are ignored and must be mounted manually.

An unmounted drive cannot be accessed through the normal tools (pcmanfm, ls, cd, etc.)

Automatic mounts by the desktop are to directories in the form /media/<username>/<volumelabel> e.g. /media/pi/mydisc

Things in fstab get mounted wherever fstab says but only automatically during boot. Use

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sudo mount -a

or

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sudo mount /path/to/mountpoint

to mount them after hotplug.

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lsblk

will show you what devices you have, what partitions they contain, if and where they are mounted (nothing in the MOUNTPOINT column means not mounted). Your USB drive should appear at least as sda and sda1. If there is no sda1 (or sda followed by any number) there are no partitions on the drive.

[Kronix]

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lsblk

will show you what devices you have, what partitions they contain, if and where they are mounted (nothing in the MOUNTPOINT column means not mounted). Your USB drive should appear at least as sda and sda1. If there is no sda1 (or sda followed by any number) there are no partitions on the drive.

So my drive doesn't have any partitions? How does that even work? Can I find the missing partitions and therefore files?

[thagrol]

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lsblk

will show you what devices you have, what partitions they contain, if and where they are mounted (nothing in the MOUNTPOINT column means not mounted). Your USB drive should appear at least as sda and sda1. If there is no sda1 (or sda followed by any number) there are no partitions on the drive.

So my drive doesn't have any partitions? How does that even work? Can I find the missing partitions and therefore files?

I've no idea whether your drive has any partitions. You need to run either lsblk or sudo lsblk with the drive connected and examine the output.

[FTrevorGowen]

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lsblk

will show you what devices you have, what partitions they contain, if and where they are mounted (nothing in the MOUNTPOINT column means not mounted). Your USB drive should appear at least as sda and sda1. If there is no sda1 (or sda followed by any number) there are no partitions on the drive.

So my drive doesn't have any partitions? How does that even work? Can I find the missing partitions and therefore files?

I've no idea whether your drive has any partitions. You need to run either lsblk or sudo lsblk with the drive connected and examine the output.

I would add that whilst "Imager" may "format" a drive (somewhat "indirectly") that, assuming you mean the Imager tool in Raspberry PiOS, is not its main purpose (which is to write O.S. images, which include "partitions" etc.). One of the main Linux tools for that is GParted which may appear under "System Tools" if it is installed by default. (It's quite a while since I installed legacy "Buster" on the P400 I'm posting from and I'm not sure if I had to install it or not.)
Trev.

[Kronix]

I have already tried both things, and:
1. When using

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sudo lsblk

, no non-system drives are listed, and
2. GParted doesn't show or list the drive.

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user@raspberrypi:~ $ sudo lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
mmcblk0     179:0    0 29.8G  0 disk 
├─mmcblk0p1 179:1    0  2.2G  0 part 
├─mmcblk0p2 179:2    0  512B  0 part 
├─mmcblk0p5 179:5    0   32M  0 part 
├─mmcblk0p6 179:6    0  256M  0 part /boot
└─mmcblk0p7 179:7    0 27.4G  0 part /
zram1       254:1    0  3.6G  0 disk [SWAP]
zram2       254:2    0  3.6G  0 disk /zram

[thagrol]

Do you have another computer you can test the drive with? If it works on there try a repartion and reformat.

[Kronix]

Before I saw this post, yes, I tried it on two Windows computers: first one couldn't detect it, second one said it had limited connection. I am guessing limited connection means it's not being able to copy files because there isn't enough transfer speed.

Also, I tried troubleshooting the drive on Windows, it said there were no problems detected.

[Kronix]

For new people:

To recap, I had problems with file permissions on my USB drive, so I reformatted it to FAT32 with Imager, after moving all of the files from it into a backup folder. I then tried to move the files back, but failed midway and now I can't open my USB or do anything.