[linux-lvm] mirror_region_size default: 4096 six times faster than 512?

[Les Mikesell]

On Thu, Feb 23, 2012 at 10:46 AM, Ray Morris <support at bettercgi.com> wrote:
> 512 byte sector consumer SATA drives from Seagate and Hitachi. Drives
> attached to a 9560 RAID card exhibited more difference than drives in a
> different system attached to the motherboard directly. As I mentioned, I
> haven't done extensive or highly scientific testing, but in general, across
> various hardware using various software, copying chinks of a few MBs seems
> to always beat copying bytes or KB per chunk.


What kind of RAID?  Anything that involves parity is going to require
small writes to read and merge the new data into blocks and rewrite
the parity.

-- 
  Les Mikesell
    lesmikesell at gmail.com