[Tfug] Solution---Crappy USB LVM/Software RAID10 performance?

[Bowie J. Poag]

Found the problem.

The motherboard on my Linux box is an old MSI motherboard from 2004, and 
uses a stock USB 2.0 (read: NOT a "High Speed USB 2.0") chipset from 
ATI. The box is running an admittedly ancient version of Linux, Fedora 
Core 6 x64.

The kernel module responsible for handling that chipset doesn't 
distinguish between "USB 2.0" and "High Speed USB 2.0".. It only 
distinguishes between USB 1.1 and USB 2.0. It will just see the hardware 
as USB 2.0 and report it bogusly as "High Speed USB 2.0" at load time.* 
Damned dirty lies! There's a bug filed against it and everything.

So anyhoo, I disconnected one of the drives (was nice to see the RAID 10 
continued to work at this point, incidentally), took it over in the 
other room benchmarked on my Hackintosh laptop, and it hauled ass.... 
39.5MB/sec versus 19.5MB/sec.  It's a USB issue. Problem solved.

Cheers,
Bowie

(* = I got to use the word "bogusly" today.)