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Re: RAIDframe and alignment on 4K-sector disks?



    Date:        Sun, 18 Jun 2017 09:49:14 -0500 (CDT)
    From:        "John D. Baker" <jdbaker%mylinuxisp.com@localhost>
    Message-ID:  <Pine.NEB.4.64.1706180933330.6459%david.technoskunk.fur@localhost>

  | (My habit is to start 512n PeeCee bootable disks at sector 1 and thereafter
  | align to the disklabel-reported cylinder size).

These days just forget the cyl size, it is complete fiction, the only
relationship it has to anything are that it causes the silly '*'s to be
added to the comments in disklabel output (we should just remove those).

  | I'll start at sector 8 and round up the sizes accordingly.

Why not just start at sector 2048 and be happy forever, whatever the drive
gets used for.  Wasting 1MB on a multi-TB drive is so inconsequential that
even considering the issue costs more (in lost time) than the space costs...

Then set the first partitition size so it ends at an even number of (binary)
GB (so it will be 1MB smaller than a nice power of two size) and everything
after that to the end, just make them nice binary sizes of GB (GiB).

Then you keep alignments that will be suitable for any use, and sizes that
will be consistent, regardless of variations that cause cyc sizes from 
different drives to be (sometimes) generated differently (and not necessarily
rationally aligned.)

kre



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