Jtdcftul

My 16GB USB pen drive mounts as read-only on Ubuntu 17.10. I've searched for all known solutions for the issues on stackoverflow, stackexchange, ubuntu forums etc for the errors popping up in output of kernel messages via dmesg when pen drive is plugged in (pasted below). I tried reformatting/checking on mac, windows & on a desktop with Opensuse, as per most suggestions.

List of suggestions on different forums/blogs I tried:



1. changing file permissions, changing owner & changing group (permission denied!)

2. manually mounting with rw options/via fstab entries (fails!)

3. running dosfsck/fsck.vfat/fsck.fat/fsck.msdos on the USB drive (fails!)

4. running dosfsck/fsck.vfat, followed by wipefs -fa <device>  & remounting (no errors but drive still read-only)

5. reformatting the USB drive with VFAT/FAT32 on linux using gnome.disks (refuses to re-format-says drive is busy). But with fdisk & mkfs.vfat, I can reformat. It works initially but after removing the drive & reinserting it, it mounts as read-only.

6. reformatting the USB drive with VFAT/FAT32 on OS X with disk utility & also windows. (drive still read-only on Ubuntu but works in rw mode on mac, windows & Opensuse)

7. reformatting with gparted (pen drive still read-only!)

8. Deleting 1st MB with mkusb, as an alternative to dosfsck/fsck.vfat & reformatting again either with mkdosfs/mkfs.vfat (works fine but if removed & mounted on OS X or windows to transfer files, it starts to mount as read-only on ubuntu! )

9. I tried different partitionings - GPT, MBR (MSDOS) on Ubuntu, Mac & also windows but only VFAT file format. Nothing helps!

10. I even tried it on 2 other pen drives I have, one of them brand new & unused. It still fails. So I am now 100% sure the problem is with Ubuntu.



I couldn't replicate this problem on an OS X, windows or on an OpenSUSE desktop, the drive mounts in rw mode on all these regardless of whether the pen drive is VFAT/FAT32 & formatted on OS X, opensuse or windows.

This same drive works perfectly fine (in rw mode) on OpenSUSE, OS X & Windows.



Any help/advice/suggestion is greately appreciated! Thanks :-)    

[27727.611477] sd 6:0:0:0: [sdb] 15155200 512-byte logical blocks: (7.76 GB/7.23 GiB)

[27727.612376] sd 6:0:0:0: [sdb] Write Protect is off

[27727.612379] sd 6:0:0:0: [sdb] Mode Sense: 43 00 00 00

[27727.613283] sd 6:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

[27727.619867]  sdb:

[27727.623082] sd 6:0:0:0: [sdb] Attached SCSI removable disk

[28362.122967] VFS: busy inodes on changed media or resized disk sdb

[28365.571735] usb 3-2: USB disconnect, device number 51

[28365.637319] FAT-fs (sdb): unable to read boot sector to mark fs as dirty

[28398.325111] usb 3-2: new high-speed USB device number 52 using xhci_hcd

[28398.467558] usb 3-2: New USB device found, idVendor=090c, idProduct=1000

[28398.467561] usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3

[28398.467564] usb 3-2: Product: USB DISK

[28398.467566] usb 3-2: Manufacturer: SMI Corporation

[28398.467568] usb 3-2: SerialNumber: 17090108010965

[28398.468463] usb-storage 3-2:1.0: USB Mass Storage device detected

[28398.468878] scsi host6: usb-storage 3-2:1.0

[28399.784653] scsi 6:0:0:0: Direct-Access     SMI      USB DISK         1100 PQ: 0 ANSI: 4

[28399.784961] sd 6:0:0:0: Attached scsi generic sg2 type 0

[28399.786492] sd 6:0:0:0: [sdb] 15155200 512-byte logical blocks: (7.76 GB/7.23 GiB)

[28399.787402] sd 6:0:0:0: [sdb] Write Protect is off

[28399.787404] sd 6:0:0:0: [sdb] Mode Sense: 43 00 00 00

[28399.788319] sd 6:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA

[28399.794763]  sdb:

[28399.797913] sd 6:0:0:0: [sdb] Attached SCSI removable disk

[28399.955739] FAT-fs (sdb): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.

The log messages

[28362.122967] VFS: busy inodes on changed media or resized disk sdb

[28365.571735] usb 3-2: USB disconnect, device number 51

[28365.637319] FAT-fs (sdb): unable to read boot sector to mark fs as dirty

show that you removed the USB drive before the system was finished updating it, so that it's in an inconsistent state.

The last message

[28399.955739] FAT-fs (sdb): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.

tells you what to do. These commands will probably help you:

sudo umount /dev/sdb

sudo fsck.vfat -w -y /dev/sdb

Of course, read man umount;man fsck.vfat;man fsck first.