Code review comment for lp:~oddbloke/cloud-init/lp1460715

some comments inline.
other thing.. it seems like it would make sense to partition assuming sectors of 4096 bytes. just to ensure alignment or to round all partition sizes to 1MB or even 4MB.

if the user has just given us such course grained data as percentage, it seems we have some wiggle room to work with and should try to do same things.

for reference it seems that /sys/block/sda/queue/hw_sector_size has sector sizes. i'm not sure that i'd bother caring though wether there was 512 or 4096 there. I'm thinking just easiest to never partition in smaller units than 4096.