I have been looking for about a week now at possible RAID options for the home file server I'm building. At first I was looking at RAID 5, but then read RAID 10 has faster read/writes. A few people wrote that if I went with a RAID 10 I should just go with a software RAID because there wouldn't be parity calculations.
So I am wondering, which would be better for a file/media server, RAID 5, or 10 (or is there a better alternative)? And would it be worth the 200-300 dollars to get a RAID card?
Assuming the file server will be accessed over a LAN, then the performance bottleneck is likely to be the network, not the hard drives. In this case, I wouldn't opt for RAID 10 just on performance grounds.
A proper hardware RAID card is an expensive way to avoid the RAID 5 write hole. I believe that software RAID 5 - at least for mdadm - can avoid this problem using the resync feature; but power loss during a write and failure of one drive may still result in silent corruption.
Another alternative is RAID-Z in ZFS, which does not suffer from the write hole problem, yet it provides the same level of redundancy as RAID 5 (or RAID 6). There are several other benefits with ZFS. ZFS is natively supported in OpenSolaris, FreeBSD and FreeNAS.
