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Re: Sysinst creates gaps between GPT partitions - why?



Martin Husemann <martin%duskware.de@localhost> writes:

> On Mon, Aug 03, 2020 at 11:08:22AM +0200, Matthias Petermann wrote:
>>            2          32         Pri GPT table
>>           34        2014         Unused
>
> That part is expected...

Not to me, entirely.

I get it why 0, 1 and 2-33 are GPT.

I get it why we don't align to 63 (because there is no good reason,
and because it doesn't line up with 4K physical sectors).

The forced choice these days is 8, because of 4K sectors.  I can see why
picking 8 for alignment isn't future-proof against the disk announced
next week with 8K or 32K physical sectors (yes, I'm making that up, but
I would not be shocked to see that over the next 10 years)..

>>         2048      262144      1  GPT part - EFI System

But 2048 is 11 bits of sector address alignment, and wastes an entire
MB.  Yes, that doesn't really matter on a 4T disk, but on a 256 MB flash
drive it seems like a lot.  (I'm perhaps overly sensitive, having used
Unix on a machine with 2 disks of 2.5M each.)

Perhaps people are expected to have partitions with integer numbers of
MB, and thus all start/end will then line up with addresses with 11 bits
of zeroes.

If everybody else thinks that this is overly aligned but that it doesn't
hurt, that's fine -- I'm not trying to agitate to change it.  I would
just like to understand if there is a good reason to align to 2048
sectors, vs 64 or 256.


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