[CentOS] OT: AF 4k sector drives with 512 emulation

[m.roth at 5-cent.us]

Chris Murphy wrote:
<snip>
> The emulation implementations don't come into play if the alignment is
> correct from the start. The better implementations have significantly
> less pathological behavior if alignment is wrong, but that's
> anecdotal, I don't have any empirical data available. But I'd say in
> any case you want it properly aligned.

You really, really want it properly aligned. We ran into that problem when
we started getting 3TB drives a couple-three years ago. Proper alignment
made a measured... trying to remember, but I think it was at *least* 20%
difference in throughput.

Alignment's easy: using parted (the user-hostile program), if you do go in
with parted -a optimal /dev/drive, and do
mkpart pri ext4 0.0GB 100% (for non-root drives, for example), it's
aligned correctly.

        mark