Re: Calculating optimal disk partitions

[Chris Murphy]

On May 9, 2013, at 8:20 AM, address@hidden wrote:
>  In the meantime, do you mind if I post a pointer to our conversation here 
> back on the Debian User list for anyone that might be following it there?

No, feel free.

> 
>> 
>> It's possible in your case the warning is about another partition which isn't
>> aligned, rather than the new one you're trying to create. If that's the 
>> case, the
>> error message is misleading.
>> 
>>> 
>>> What about a 4096 physical sector drive?
>> 
>> Alignment on a 4Kn AF HDD is also a non-factor. There's nothing to align. 
>> But I
>> still think the default is 1MB alignment with new versions of parted. As a 
>> data
>> drive, they work. For boot drives, even recent firmware, let alone older 
>> firmware,
>> don't like them at all.
>> 
>> For 512e AF HDD, alignment is a considerable factor depending on the firmware
>> implementation. It's best to align.
> 
> I would be more than happy to put together any helpful documentation if you 
> or someone else would give me some guidelines on what to put in it.

The simplest rule of thumb is to start a partition at 1MB, and specify all 
partition sizes in whole MB's. It solves this, and maybe also for SSDs. The 
open question is some SSDs have 2+MB erase block sizes and it's not clear if 
there's a benefit, or even a way, to partition on 2MB boundaries. Any recent 
partition tool starts the first partition on a 1MB boundary.

Chris Murphy