Sector-size and advanced format (4k) disks

Louie Cardone-Noott lcn at
Tue Sep 5 18:20:52 UTC 2017

Hi Trond,

Thanks for your reply.

On 05/09/2017 14:06, Trond Endrestøl wrote:
> Changing the sector size is not recommended according to newfs(8): ...

Indeed, I guess it's *really* not recommended to deviate from 512 B 
sector size then...

> Maybe Dr. McKusick's lectures can enlighten you to make a wise choice:
> Keynote Address: A Brief History of the BSD Fast Filesystem (FAST '15)

This is interesting. At 50.00 he implies that using a 32 k blocksize, 4 
k fragment-size, and 512 B sector-size is the 'right' way to use a 
modern HDD.

Based on the above I suppose my assumption that the sector-size should 
match the HDD physical sector size was wrong. Pretending that the 
sectors are still 512 B, while making everything align to 4 k, and 
letting the HDD do its magic seems to be best.


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