Linux Advanced

It can be very frustrating to try to send mail through the command line using sendmail. Although sendmail is preinstalled on most linux system, it is configured not to deliver any mail to the outside (probably to prevent spamming).

RAID1 or mirroring configuration uses two hard drives to duplicates exactly one drive to the other. This provides hardware redundancy - if one drive fails the other can continue to operate independently. Hardware RAID is provided by the controller, which present to the operating system one logical drive and the RAID management is transparent.