[Fwd: Re: regarding libata HPA default behavior]

[Matthew Garrett]

> Seems to me the dangers and damage caused by a suddenly-too-small disk 
> are greater than those caused by a suddenly-larger disk.  The latter 
> case only confuses schemes that are offset from the last reported LBA, 
> whereas the former can cause data loss and worse.

Indeed. When we transitioned to libata for pata devices, a large number 
of users suddenly had regressions. It's not just an issue for laptops, 
there's a moderate number of desktop drives that are clipped to 32GB in 
order to avoid breaking ancient Phoenix BIOSes. The traditional 
behaviour of drivers/ide has resulted in many people having file systems 
that extend into the HPA, and breaking those setups wasn't acceptable 
for us. As a result, we extend the disk by default in Ubuntu.

-- 
Matthew Garrett | mjg59 at srcf.ucam.org