Matthias,
Thank you, I never would've guessed the USB filesystem, but that's exactly where the problem is. The drive has become permanently read-only/write-protected. It must have happened when my PirateBox's external battery ran out.
My USB is a Sandisk Cruzer Fit 32GB, which seemed like a good idea for a PirateBox due to the extra-small physical size allowing for better portability. However, it seems the Cruzer Fit is notorious for becoming permanently write-protected. According to a post on the Sandisk Forums, a Sandisk representative explained it like this:
In case anyone's interested, here are the commands that revealed the problem, entered with the drive plugged in my computer:
Thank you, Matthias!
Thank you, I never would've guessed the USB filesystem, but that's exactly where the problem is. The drive has become permanently read-only/write-protected. It must have happened when my PirateBox's external battery ran out.
My USB is a Sandisk Cruzer Fit 32GB, which seemed like a good idea for a PirateBox due to the extra-small physical size allowing for better portability. However, it seems the Cruzer Fit is notorious for becoming permanently write-protected. According to a post on the Sandisk Forums, a Sandisk representative explained it like this:
So the write-protection is an intentional hardware design to protect from data loss. I would rather have a drive that loses data but can be re-formatted, than a drive that doesn't lose data but becomes write-protected/useless/bricked. I will try to return the drive for a refund, and switch to using one that's not so sensitive.Quote
"The flash drive has detected a potential fault and has become write protected to prevent data loss. There is no method to fix this. You will need to backup your data and replace the flash drive.
In case anyone's interested, here are the commands that revealed the problem, entered with the drive plugged in my computer:
$ # Unmount the partition... $ sudo umount /dev/sdb1 $ # Attempt to check the partition and fix errors... $ sudo fsck /dev/sdb1 -a fsck from util-linux 2.20.1 fsck.fat 3.0.26 (2014-03-07) open: Read-only file system $ # Attempt to set the drive's read-only setting to off... $ sudo hdparm -r 0 /dev/sdb /dev/sdb: setting readonly to 0 (off) readonly = 0 (off) $ # Attempt again to check the partition and fix errors... $ sudo fsck /dev/sdb1 -a fsck from util-linux 2.20.1 fsck.fat 3.0.26 (2014-03-07) open: Read-only file system $ # Drive is still read-only, check the dmesg buffer for more info... $ dmesg | grep "sdb" [13354.524273] sd 3:0:0:0: [sdb] 62530624 512-byte logical blocks: (32.0 GB/29.8 GiB) [13354.525422] sd 3:0:0:0: [sdb] Write Protect is on [13354.525431] sd 3:0:0:0: [sdb] Mode Sense: 43 00 80 00 [13354.527365] sd 3:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [13354.546027] sdb: sdb1 [13354.547026] sd 3:0:0:0: [sdb] Attached SCSI removable disk [13683.925837] sd 4:0:0:0: [sdb] 62530624 512-byte logical blocks: (32.0 GB/29.8 GiB) [13683.928061] sd 4:0:0:0: [sdb] Write Protect is on [13683.928067] sd 4:0:0:0: [sdb] Mode Sense: 43 00 80 00 [13683.928412] sd 4:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [13683.938979] sdb: sdb1 [13683.939978] sd 4:0:0:0: [sdb] Attached SCSI removable disk [14660.295840] sdb: detected capacity change from 32015679488 to 0 [29371.914622] sd 5:0:0:0: [sdb] 62530624 512-byte logical blocks: (32.0 GB/29.8 GiB) [29371.916154] sd 5:0:0:0: [sdb] Write Protect is on [29371.916164] sd 5:0:0:0: [sdb] Mode Sense: 43 00 80 00 [29371.916427] sd 5:0:0:0: [sdb] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA [29371.925670] sdb: sdb1 [29371.926691] sd 5:0:0:0: [sdb] Attached SCSI removable disk $ # dmesg confirms the drive is in a hardware write-protect mode.
Thank you, Matthias!