gstripe oder graid3 on USB-Sticks

[Raphael H. Becker]

Hello Ivan,

On Tue, Dec 19, 2006 at 09:54:50PM +0100, Ivan Voras wrote:
> Raphael H. Becker wrote:
> > Hello *,
> > 
> > today I bought 3 USB sticks to find out, if there's something to play 
> > with GEOM on it. My FreeBSD ist 6.2-RC1.
> 
> > umass0: BBB reset failed, IOERROR

This happened on pulling one of the three sticks. 

> As someone who had the same idea recently I can tell you that the
> problem you're seeing is almost certainly in the motherboard. My sticks
> draw ~250 mA, but it turns out my 4 USB ports are wired such that they
> all share the same 500 mA source, resulting in weird and random
> appearing errors when all three are connected.
> 
> Try finding separately powered USB ports (new motherboards often have
> them on board but lack the connectors).


I use them on a USB hub with an external power supply.

I don't think this is a power-issue cause I tried this last year using
two self powered USB2.0 HDD with geom-stripe. Same result: writing is
pretty good, reading a file using dd locks up. (6.0-RELEASE)


Maybe, I will try this next days, it is an issue about reading parallel
from different devices on a USB hub, which (probably) cannot satisfy two
concurrent tasks at the same time at the same root-hub/port.

gstripe3 was able to rebuild the RAID after re-inserting an arbitrary
stick of the 3, so USB+GEOM seems to be fine here.

Maybe this I completly unrelated to GEOM, I cannot guess this.

Regards
Raphael