File server

Planning on grabbing 3 1TB drives and putting them in RAID5 using MDADM with LVM on top.

Is it possible to protect myself from power outages? Im worried if im writing a file and a power outage occurs, i will loose the array (can that happen or will i just loose the file?).

You can protect yourself from power outages - either run this on a laptop, or get your self a UPS (uninterruptible power supply, not a nearly-adequate replacement for a postal service). These will keep your server running over short breaks in power using batteries.

Ah dont know what i was thinking, didnt even ask what i wanted to ask.

Is it possible to protect myself from power outages without using UPS/Hardware raid?

Using some file system.

the journaling function of ext3 can in theory protect your array, but it isn't perfect. What it will do, is in the event of a power failure, it will roll back the changes made to that chunk of data YOU WILL lose whatever was in the buffer however, as well as any data not fully written to disk.

but I would just spend the 100$ on a home use UPS, in the end it is a lot easier than the worst case scenario.