Because I've more or less run out of disk space on my existing small on board RAID, I've decided to build a DIY NAS/Media server (on the advice of a friend, this approach seems to be cheaper and more flexible than an off the shelf NAS). All the parts are on their way, but I've encountered a couple concerns I'm not sure about, and I wonder if anyone might have any advice:
1) I'm using normal consumer grade parts (with some NAS grade hard drives), including a run of the mill mobo and non-ECC RAM. A friend suggests I use ZFS as the filesystem on the drives, but a quick google search pulls up lots of examples of people saying not to use non-ECC RAM with ZFS. Is this really a problem worth worrying about? If so: What is a good alternative?
2) I'm trying to decide on a RAID level/arrangement to use. I'll have 6 drives, all of equal size, including two which are currently in use in a RAID 1. I want to keep risk of data loss to a reasonable minimum, so I'm currently thinking of setting up the 4 new drives in RAID 5 (RAIDZ?) and keep the older pair as separate drives for backup. The thing is that if I were to get a 7th drive to cover the full capacity of the RAID, space efficiency would only be around 42% (3 drives for backup, one drive worth for parity, 3 for actual data). Is this a bad idea? The general consensus online seems to be that RAID 5 alone isn't trustworthy, and that one should always have some form of backup, so I'm rather worried.