[clug] Advice: Overlay mounts or LVM tweaking for dual-media storage?

[Brad Hards]

On Sat, 19 Nov 2011 07:22:51 PM steve jenkin wrote:
> The 'small fast' disk to be used both as a cache and as primary storage
> for new or modified files.
> 
> The 'big slow' disk to be used for files that are a) securely backed up
> elsewhere and b) are low-frequency use.
> 
> As files are backed up from the small-fast disk, they are to be copied
> to the big-slow-disk and deleted from the s-f-d unless tagged as 'keep
> in cache' (hmmmm. not sure just yet how to do that!)
I haven't tried it yet, but bcache (http://bcache.evilpiepirate.org/) sounds 
close to what you're looking for. A more recent update: 
http://lwn.net/Articles/458417/

Brad