Using USB2.0 hard drives (performance) on FreeBSD 5.3

[Forrest Aldrich]

I need extra disk space on one of my machines (in short order).   So I 
decided to experiment with attaching a USB2.0 hard drive (Maxtor 
OneTouch) to the system (SIIG PCI controller).  I use a OneTouch on my 
Windows/XP sytem and it works really well.

I wanted to explore placing my mailstore on an external USB2.0 drive - 
would be easy to port the data to another system if I needed.

However, in experimenting with replicating some data (via rsync), I'm 
wondering if this is a bad idea.   While rsyncing data over the wire to 
the USB2.0 drive (mirroring some data, basically), the shell response to 
something like "ls" would hang (eventually completed, but much later).

I wonder if someone can advise about the use of this drive for that 
purpose (mailstore) and if there may be some tunables I would need to 
tweak to get better performance.


Thanks.