ubuntu 9.04 server nas

[RHead]

Hi i'm using Ubuntu 9.04 server to use fileserver. I have problem with dos problems. My previuos setup was windows nt server (pentium 2, 20gb hd , 1gb ram) now athlon x 4400 2 gb memory, 2x250gb raid 0+1). Client are running old dos program. There thousands of small files witch dos based program uses. With new system file handling is very slow. Is there guide to tune server ??

Client are Windows Xp clients