Partitioning in again one of the topics on which many holy wars have been battled upon, so I'll try to be only informative here about my setup, allowing you to choose another setup if it fits your needs better.
Ideal solution from the standpoint of data safety would be of course mirrored RAID (RAID 1) - two disks that both store the same data and provide redundancy in case of single disk failure. This setup was my initial intention (I've even bought motherboard with decent RAID controller), but after some additional thoughts I've figured out that two separate disks can be used in a better way. Main reason why I've give up on RAID is noise - since it uses two disks for storing data that can fit on only one, it generates twice as much noise. Second is that I've mounted disks with additional disk silencers so I physically didn't have space for more disks inside my case.
Solution that works for me is following: one very reliable, but relatively small disk holds root partition and TV cache (both of which have very frequent read/write cycles that shortens disk's lifespan). Root partition holds only programs and configuration, so it is small enough to be easily backuped after every significant configuration change. Second partition was for TV cache, because in my experience MythTV works best with whole partition available for recordings - beer in mind, however, that this partition will be written upon every second, 24/7, eating your hard drive more quickly. However, since this disk holds only data that is regularly backuped (root partition) or is irrelevant (MythTV cache data), I'm calling it a "disposable" disk, because even if it fails I'll be able to restore it relatively cheaply.
Another disk is large and slow one (slow disks theoretically should have longer lifespan) that holds my music, movies, pictures etc. which I'm calling a "HTPC storage" and I'm praying regularly for it not to die :). Seriously, this disk can not be backed up since it is too large, but read/write cycles on it are rare and I'm changing it every year or so with newer and larger model of best manufacturer, so chances for it to die with all my data on it are minimal. Additionally, I'm checking its S.M.A.R.T. status regularly and on any sign of trouble I'll change it with another unit.
Finally, this is partitions layout for two disks in my box:
- Disposable disk:
- Root partition (cca 10 GB, backuped regularly)
- Partition for TV cache (cca 10 GB, disposable)
- HTPC storage
Large disk:
- HTPC storage
Second disk is enormous one that can solely store all of your HTPC data and it is accessed only occasionally, meaning less fear of malfunction over years.
