[SOLVED] 32GB USB drive mounts Read Only while 4GB mounts RW

CollieJim · 06-12-2020, 03:37 AM

When I tried to mount my new 128GB microSD card I got exfat unknown message.
I installed exfat-fuse and exfat-utils, and now the card can be mounted, but only as readonly.

I tried mounting a vfat 32GB card with the same result - readonly.
A vfat 4GB card mounts RW.

I get the same results both as user and root.

How can I mount the larger cards RW?
Thanks

edit: root filesystem is ext4.

fatmac · 06-12-2020, 04:22 AM

Personally, I would just put an ext4 filesystem onto them, like I do with all my drives, internal & external.

CollieJim · 06-12-2020, 06:27 AM

I wii do that, but I have several 32GB cards with data that I need to access.

wpeckham · 06-12-2020, 06:39 AM

Quote:

Originally Posted by CollieJim

I wii do that, but I have several 32GB cards with data that I need to access.

You can access the data on a device mounted RO, you just cannot change it easily.

colorpurple21859 · 06-12-2020, 11:06 AM

I’m probably wrong but I don’t think linux has full exfat support. Why not use ntfs?

ehartman · 06-12-2020, 12:38 PM

Quote:

Originally Posted by CollieJim

I wii do that, but I have several 32GB cards with data that I need to access.

exFAT is - because of M$ copyrights ON it - never fully supported in Linux.
So reading/copying FROM it will work, modifying is always a risc.

Timothy Miller · 06-12-2020, 12:51 PM

The fuse exfat driver is pretty reliable. It's not 100%, but it's not that far off. I have never run into any issues and all my USB's are formatted exfat from 2GB to 128GB.

CollieJim · 06-12-2020, 10:31 PM

I suspect that either exfat-fuse or exfat-utils changed something in my system. Before installing them I had full RW access to 32GB vfat cards. Now I do not.

Timothy Miller · 06-12-2020, 11:04 PM

Vfat or Exfat? They're different filesystems. Vfat is Fat16/Fat32. Exfat is...well...exfat, it was designed to replace fat32. If you're trying to access vfat partitions, then exfat driver shouldn't even be loading. Also if vfat for any reason detect an "unsafe removal", the flag on fat32 for that will prevent it from being written to on linux, and the only way to fix it is to do a "scan and repair" from windows or a dosfsck to fix the flag.

ehartman · 06-13-2020, 02:27 AM

Quote:

Originally Posted by Timothy Miller

Vfat is Fat16/Fat32.

Actually even Fat12 too, although that is only used on media < 8 MB (like floppies).

CollieJim · 06-13-2020, 07:11 AM

32GB problem solved - it had an ISO image on it. Not quite sure why I was able to mount it as /dev/sdb1 though.
128GB will get ext4.