This is not a bug in sgdisk; it's either a bug in the charm or an incorrect use of same. Specifically, the sgdisk command shown is:
sgdisk --zap-all --clear --mbrtogpt /dev/vdb This command does four things, in sequence: - It zaps all GPT and MBR data structures (--zap-all). - It creates an empty GPT data structure (--clear). - It OKs the conversion of any MBR data structure to GPT form (--mbrtogpt). - It writes the resulting changes to disk. (This is implicit in most uses of sgdisk.) The first and second of those options are both used to wipe data, but in different ways -- --zap-all zeroes out all the sectors of the disk used by the GPT data structures, whereas --clear erases the partitions but leaves the data structures intact. Using --clear after --zap-all should therefore have the same effect as using --clear alone. (There may be cases where --zap-all would be necessary if you're dealing with a damaged disk, but I'd need to study this some more to be sure.) In any event, the end result of those two commands is a GPT disk with no partitions defined, not a disk without a partition table. The --mbrtogpt option is useless in this context. It should be used when you want to convert an MBR disk to GPT form, but as the preceding options set the disk up as GPT, --mbrtogpt does nothing. If the goal is to completely erase all partition data, including the partition table itself, the following command should be used: sgdisk --zap-all /dev/vdb Adding --clear and --mbrtogpt will be useless at best, and as you've discovered, --clear adds an (empty) partition table back. Note also that parted does *NOT* show that the disk is "all clear," as described in the bug report: # parted shows that it's call clear % parted /dev/vdb print Model: Virtio Block Device (virtblk) Disk /dev/vdb: 21.5GB Sector size (logical/physical): 512B/512B Partition Table: gpt Number Start End Size File system Name Flags Note the line that reads "Partition Table: gpt," which indicates that a valid GPT is present on the disk. No partitions are listed because that was the effect of the --clear option to sgdisk. Naturally, fdisk also notes the GPT data structures in the protective MBR. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to gdisk in Ubuntu. https://bugs.launchpad.net/bugs/1303903 Title: sgdisk zap/clear doesn't wipe all GPT tables To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdisk/+bug/1303903/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
