DNS and Mail Maintainence
 

How can I maintain DNS and mailserver for better performance.
Specially, some times I get disk errors and bad sectors in /var partition which used by both (DNS and MAIL).

Is there any cache or directories that must be maintainded, or cleaned periodically?

If you're getting bad sectors then I'd advise you to swap out the hard disk ASAP... AFAIK there is little maintanence to be done for your DNS. You using BIND? If so I think its just updating your root hints file (the file that lists the root name servers, you can use 'dig' for this) occasionally. When you say mail server do you mean sendmail or the user access side of things using a POP/IMAP daemon. If its the latter then what software are you using?

Cheers.

Jamie...