Magic Pocket is a block storage system, and all storage in it is append only. We'll go into more detail on the on-disk format in a blog post. But, yes, we use

Magic Pocket is a block storage system, and all storage in it is append only. We'll go into more detail on the on-disk format in a blog post. But, yes, we use the SMR disks on an HBA, and we directly address the disk on a LBA (and zone) basis.