Re: ahcisata poor performance

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Sat, Jul 26, 2014 at 01:05:05PM +0400, Dima Veselov wrote:
> Sorry, I have lost your last message, but wish to know something about
> 4k-alignment. What should be aligned to what?

I suspect it is something like:

# gpt show wd0
       start        size  index  contents
           0           1         PMBR
           1           1         Pri GPT header
           2          32         Pri GPT table
          34          30         
          64    14680192      1  GPT part - NetBSD RAIDFrame component
    14680256    33554432      2  GPT part - NetBSD swap

Note how I didn't start index 1 at the default 34 (512 byte blocks
= offset of 17408 bytes which is not divisible by 4k = 4096 bytes),
but used gpt add "-b" to start at 64 (i.e., offset of 32768 bytes which
is divisible by 4096).

(and
14680256*512/4096
1835032.00000000000000000000
)

Cheers,

Patrick