Can't write to USB drive <solved>

[herrMnnn]

Sorry for all the questions, folks, but TC/Linux has a very steep learning curve and I am worn out from searching...

I am booting version 4.5.2 of Core to a command line.  It was installed onto sda1 (internal flash) using the installer program in CorePlus, selecting text only install, no extensions.

I need to write data to sdb1 (a removable flash drive) from a python script.  I previously had this running under TinyCore but want to run it with just the Core base.

When I try to write to the USB drive I get a permission denied error (either from the script or just with an echo command from the command line).  If I sudo the same command it works fine.

Mount returns:

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/dev/sdb1 on /mnt/sdb1 type vfat (rw,relatime,fmask=0022,dmask=0022,codepage=cp437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro)
/etc/fstab contains the line:

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/dev/sdb1       /mnt/sdb1       vfat     noauto,users,exec,umask=000 0 0 # Added by TC
ls -l in the /mnt directory gives me:

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drwxr-xr-x    4 root     root          1024 May 19 10:51 sda1/
drwxr-xr-x    4 root     root         16384 May 19 12:17 sdb1/
sudo chmod 777 /mnt/sdb1 has no effect on the permissions of the directory.

What do I need to do to get universal access to the usb drive?  I guess I could run the script as root, but that doesn't seem right...

NB The system will be running unattended, so all settings need to survive a reboot after a power failure.

[Rich]

Hi herrMnnn
Did you mount it using  sudo mount /dev/sdb1 /mnt/sdb1 ?
Try using  mount /dev/sdb1  instead.

[herrMnnn]

Thanks Rich.

It's mounted when I boot, TC appears to be doing it for me at boot time.  The entries in fstab were put there by TC or the installer or something, I haven't edited that file.

here's an example of what I get from the mount command:

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tc@box:/mnt$ sudo umount /mnt/sdb1
umount: can't umount /mnt/sdb1: Device or resource busy
tc@box:/mnt$ mount /dev/sdb1 /mnt/sdb1
mount: you must be root
tc@box:/mnt$ sudo mount /dev/sdb1 /mnt/sdb1
mount: mounting /dev/sdb1 on /mnt/sdb1 failed: Device or resource busy
tc@box:/mnt$

I'm also a bit confused as to why chmod doesn't affect the permissions for the directory:

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tc@box:/mnt$ ls -l
total 17
drwxr-xr-x    4 root     root          1024 May 19 10:51 sda1/
drwxr-xr-x    2 root     root         16384 Jan  1  1970 sdb1/
tc@box:/mnt$ sudo chmod 777 /mnt/sdb1
tc@box:/mnt$ ls -l
total 17
drwxr-xr-x    4 root     root          1024 May 19 10:51 sda1/
drwxr-xr-x    2 root     root         16384 Jan  1  1970 sdb1/
tc@box:/mnt$

[curaga]

You can't set the permissions because it's fat32, no support for permissions in that FS.

Try "sudo remount /mnt/sdb1 -o uid=1001,gid=50". It may need a full umount/mount instead of remount, but try anyway.

[Rich]

Hi herrMnnn

It's mounted when I boot, TC appears to be doing it for me at boot time.

TC won't mount a drive just because it finds it. There's probably a tce or cde directory on it that's
causing that to happen. What does  ls /mnt/sdb1  give you?

[herrMnnn]

You can't set the permissions because it's fat32, no support for permissions in that FS.

Try "sudo remount /mnt/sdb1 -o uid=1001,gid=50". It may need a full umount/mount instead of remount, but try anyway.

Hi herrMnnn

It's mounted when I boot, TC appears to be doing it for me at boot time.

TC won't mount a drive just because it finds it. There's probably a tce or cde directory on it that's
causing that to happen. What does  ls /mnt/sdb1  give you?

Is there a forehead slapping emoticon I can use?   

I must have put a mount command in /opt/bootlocal.sh at some time along the way. I was sure I hadn't but no-one else could have done it so I obviously did.

Adding the uid and gid options as per curaga's post has it all working.

Thanks for being so patient and helpful. I am learning a lot from this forum and just from researching solutions to the problems I seem to create for myself.  I have toyed with Linux several times over the past 10-15 years or so but never stuck with it. Tiny Core however is such an elegant solution that it has encouraged me to persist.

[curaga]

Haha, "remount" I'm getting old, obviously. Should have been mount -o remount.