yay, it eventually finished

@Rotonen ashift=0, disk block size 4096

``` Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes ```

i can only assume ashift 0 to mean 'whatever the disk lied to me at creation time'

yup, apparently hardware manufacturers lie

run dmidecode and despair