Many flash controllers keep remapping tables and reserved areas; a single dd wipe of user area may not reach controller metadata. Use multiple complementary steps:
A. Use blkdiscard (for devices supporting TRIM/discard)
B. Overwrite with multiple patterns (addresses remapped blocks via wear-leveling) au87101a ufdisk full
C. Use vendor-specific SCSI/USB passthrough commands (advanced)
D. Use wipefs to clear signatures
Notes:
The primary causes of the UFDisK full condition on AU87101A are: Many flash controllers keep remapping tables and reserved
Use a standard OS command if available (e.g., df -k /au87101a). If the OS doesn’t mount the volume directly, you will rely only on ufdisk output.
If a technician enabled verbose debugging and forgot to turn it off, the system might log every operation, filling the ufdisk in hours or days. Optional: repeat the random→zero cycle twice to increase
On some embedded systems, you can repartition the flash. This requires advanced skills and may void warranty. If allowed, allocate more space to ufdisk from a less-critical partition.