[dm-devel] Device Mapper as a cache for SAN?

[Eric Van Hensbergen]

It seems like device-mapper would allow a fairly straightforward
implementation of a local-disk cache for a SAN (iSCSI, AOE, etc.).  
The dm-raid1 and dm-mpath modules seem to have elements of overlap,
but its not clear if there's a straightforward way to implement a
local-disk block cache using existing modules, or whether a new one is
needed.  Has anyone looked at this before?

          -eric