Adaptect raid performance with FreeBSD

[Ari Suutari]

Hi,

On Wednesday 14 January 2004 15:20, Karl Pielorz wrote:
> > So, I get only about 25MB/s. Shouldn't I be getting something
> > like 70 MB/s, or even more since there are two disks that
> > can server read requests ?
>
> Hmmm, what happens if you run two of those at once?

	Running 5 dd's at once gives in iostat:

      tty             da0              da1             acd0             cpu
 tin tout  KB/t tps  MB/s   KB/t tps  MB/s   KB/t tps  MB/s  us ni sy in id
   1  146  0.00   0  0.00  64.00 473 29.58   0.00   0  0.00   0  0  1  1 98
   0   38  0.00   0  0.00  64.00 625 39.06   0.00   0  0.00   0  0  2  1 97
   0   38  0.00   0  0.00  64.00 492 30.76   0.00   0  0.00   0  0  2  1 97
   0   38  0.00   0  0.00  64.00 506 31.62   0.00   0  0.00   0  0  1  0 98
   0   38  0.00   0  0.00  64.00 495 30.94   0.00   0  0.00   0  0  1  1 98

	The peak seems to be 39 Mb/s.
>
> But, I can't remember seeing adjusting it making any real-world difference
> - what happens if you max it out (e.g. 128, or 256)?

	I'll have to try this. However, I also doubt that it is not going
	to change anything.
	
		Ari S.

-- 
Ari Suutari
Lemi, Finland