So I aquired a SeaGate 4-bay business NAS from a garage sale with four 4TB drives. I set everything up, ran some diagnostics and everything looked grand. This unit had hardly ever been used. Practically out of the box. I am running it currently running it in RAID 5. Since everything looked good, I transfer all of my media (Approximately 6TB worth) to it.

Well today (this is where I fucked up) I was just thumbing through the settings trying to see what all this unit could do. I cam across the MTU size setting and it was set at 1500. I read through some stuff online and since I had gigabit Ethernet, I thought that I understood that I could up that number....to 9000. I immediately noticed that it was not running well at all. When I attempted to go to the dashboard to revert my settings, I found that it was running absurdly slow. So slow in fact that it wont load any of the settings. When I try and access the network settings page I just get a 404.

Any ideas on how to fix this? Id be very distraught if I had to lose all my data over this.

*Edit It also appears I cannot access all of my media. When I check the properties of the folder, it is only showing 250 of the 2500 files on the NAS