This is actually a server at home, but I felt it was sufficiently complicated as to not have it on SuperUser and could easily apply to a professional situation.

I have a file server running Debian (Lenny 5.0.4), and it has an XFS LVM on top of a RAID 5 with the OS drive separate from the RAID. It's also running apache, samba, and postgresql. Side note: before anyone asks, I'm using RAID5 because I get more bang for the buck on raw drive space, and still have some fault tolerance.

When the box is started (via shutdown or reboot) reading/writing to it's samba share maxes out the gigabit network connection. Over time, this slowly degrades eventually becoming < 10MB/s; however, when rebooted the speed returns to maxing out the connection.

Why is this happening, and is there a way to 'clear' out whatever's causing it without taking the server down?

Thanks in advance!