People don't tend to use parity RAID primarily for uptime, they do it because it's cheaper - HDD costs for a mirror/striped-mirror implementation are always 1/N, whereas with a RAID-6 it's 1-(2/N), or 1-(1/N) for RAID-5.
In my experience, mirrored and/or striped-mirror type RAID implementations are more reliable, performant, and easier to maintain than any variation of parity RAID. Even for a home setup, it's just not worth my time.
> People don't tend to use parity RAID primarily for uptime/multiple drive failures, they do it because it's cheaper - HDD costs for a mirror/striped-mirror implementation are always 1/N, whereas with a RAID-6 it's 1-(2/N), or 1-(1/N) for RAID-5.
A few years ago I built a home NAS. Back then, maximum drive sizes were 3TB for 3.5", and 1TB for 2.5". The tiny ITX case I had had one 3.5" slot, and one 5.25" slot.
So, I could either do a RAID1 with 2x3TB 3.5" disks; or get a 6x2.5" adapter for the 5.25" bay and do a RAID5/6 with 7x1TB for a net capacity of 5/6 TB.
I'm still not sure whether it was a good idea – the hardware looks a bit adventurous: http://dl.creshal.de/IMG_0873.JPG and was loud as hell –, but it worked well for about five years without any drive failures.
(Then I replaced it with a smaller NAS with 2x2TB drives in RAID, because as it turned out, my interests went from binge-watching storage intensive TV series to reading more books, and I never ended up using more than 1TB storage anyway.)
In my experience, mirrored and/or striped-mirror type RAID implementations are more reliable, performant, and easier to maintain than any variation of parity RAID. Even for a home setup, it's just not worth my time.