GEOM stripe + concat

[Sergey Lungu]

On Sun, 22 Jan 2006 19:22:57 +0300 I wrote:

> Hello,
> 
> I have FreeBSD 6.0-RELEASE running on my FTP server. There are three
> disks on that box: two identical 120GB and one 300GB. I am using
> gvinum for stripping between first two disks. I am going to give
> gstripe a try, sine gvinum is too unstable.

Since nobody has answered my question, possibly it was too silly, I
decided to experiment a bit. I'll answer my questions:

> Am I able to concatenate created stripe with 300GB disk?

Yes, you can!

> And is it wise at all?

I have made some simple benchmarking on three different geometries.
Legend:
	a * b - stripping between a and b
	a + b - concatenation of a and b
	ad1   - 120GB disk
	ad2   - 120GB disk
	ad3   - 300GB disk

I tried to upload and then download a 700MB movie. Here are my results:

ad1 * ad2:
	Uploading:	1m8.406s
	Downloading:	1m4.656s

ad1 * ad2 + ad3:
	Uploading:	1m4.115s
	Downloading:	1m4.962s

ad1 + ad2 + ad3:
	Uploading:	1m4.110s
	Downloading:	1m4.971s

Conclusion:
There is no big difference between all this geometries in FTP context,
or possibly there are some on high load!?

-- 
Sergey Lungu

Fuzzy project objectives are used to avoid the
embarrassment of estimating the corresponding costs.