Linux tips and trics 
Sometimes when configuring servers you must configure RAID.
On branded servers they are often harware, but nonetheless, they often have to deal with a software raid.
Some ISPs provide get access to the Internet only for a specific MAC address.
You can manually change the MAC address and do not communicate with the provider for the change settings.
I have a postfix-based mail server and SpamAssassin as an antispam. There was a task to view statistics to analyze the effectiveness of antispam and the mail server settings.
I know that it is possible to make an access point from a wi-fi card. Now I tried to set it up. Here is a description of my actions step by step.
I have old laptop Acer Aspire 5315.
OS— Kubuntu 11.10
Wi-Fi-card— Atheros. That's what lspci says about it
Ethernet controller: Atheros Communications Inc. AR242x / AR542x Wireless Network Adapter (PCI-Express) (rev 01)
Of course it have ethernet card too.
Let`s go...