Graceful degradation RAID solutions?

[Pinky's Brain]

Where graceful means it uses a redundant array of drives which can fail in gradations rather than preserving either 100% or 0% of the data.

D-GRAID is an old concept ... but I see very few implementations. Basically there is unRAID and WHS with mirroring (and a couple of hacks you can do with unionfs and mirroring or FlexRAID but those are rather makeshift). Why is nearly everyone so big on striping when it offers no real advantages over non striped methods for small scale NAS? (Improvements in access time are irrelevant and cheap drives can serve big files fast enough to fill Gb Ethernet without striping.)

Are there any other solutions which use non striped redundancy, where HDs simply contain a subset of the files and which can still be accessed as a single logical volume?

 

[Blue Fox]

No standard RAID levels support anything like that due to their implementation.

 

[SockMan!]

Technically, you're talking about two different things. RAID is byte or block level that, aside from driver support, is fairly OS and file system agnostic. Implementations such as Windows Home Server depend on the OS, software, and file system.

 

[Pinky's Brain]

Edited, now lets see if we can discuss something more interesting than semantics