[Box Backup] Raid Question

[Ben Summers]

"W. Chris Shank" wrote:
> I'm wondering what the rationale is for the userland raid? Wouldn't  
> hardware raid or even md-raid (software raid) be more efficient? It  
> seems like more complex development to be re-creating raid. What am  
> I missing? I'm sure there is a good reason.

"Historial reasons". The intended platform for the (non-open source)  
deployment didn't have  good enough hardware RAID support, and  
software raid wasn't nice either. So I wrote my own. Needs must.

It could actually be more efficient once the raidfile daemon is  
written, but it's now a few years later and the original reason for  
implementation is probably no longer valid.

That said, with not too much extra work, we could have a neat system  
where you build backup servers out of clusters of three servers in  
such a way that if one goes down, the user does not notice. It's  
almost there now, except that the recovery system needs writing, and  
it would be nice to be able to write files in degraded mode. I  
estimate 5 or so days of work, including tests.

Ben