I have 32GB sd card that was flashed to a premade image using a utility some months/years ago. I want to reclaim the card and start fresh. Every attempt I have made at reformatting it and/or erasing the partition table has failed, however. Often the utilities say they did something, but the partition table still remains. Even the (very slow) attempt at wiping it with dd left the partition table intact:
$ sudo dd if=/dev/zero of=/dev/mmcblk0 bs=8192 # many hours later... dd: error writing '/dev/mmcblk0': No space left on device 3895873+0 records in 3895872+0 records out 31914983424 bytes (32 GB, 30 GiB) copied, 11577.2 s, 2.8 MB/s
The card appears to have what is known as a "hybrid mbr". I have tried
gnome-disks, and I am sure others that have been lost to my bash history. What secret incantation am I missing?
$ sudo gdisk /dev/mmcblk0 GPT fdisk (gdisk) version 1.0.5 Partition table scan: MBR: hybrid BSD: not present APM: not present GPT: present Found valid GPT with hybrid MBR; using GPT. Command (? for help): p Disk /dev/mmcblk0: 62333952 sectors, 29.7 GiB Sector size (logical/physical): 512/512 bytes Disk identifier (GUID): 6A9E3D38-090C-48BA-A14D-7682BA479872 Partition table holds up to 128 entries Main partition table begins at sector 2 and ends at sector 33 First usable sector is 34, last usable sector is 62333918 Partitions will be aligned on 2048-sector boundaries Total free space is 2014 sectors (1007.0 KiB) Number Start (sector) End (sector) Size Code Name 1 2048 67583 32.0 MiB 0C01 hassos-boot 2 67584 116735 24.0 MiB 8300 hassos-kernel0 3 116736 641023 256.0 MiB 8300 hassos-system0 4 641024 690175 24.0 MiB 8300 hassos-kernel1 5 690176 1214463 256.0 MiB 8300 hassos-system1 6 1214464 1230847 8.0 MiB 8300 hassos-bootstate 7 1230848 1427455 96.0 MiB 8300 hassos-overlay 8 1427456 62333918 29.0 GiB 8300 hassos-data