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

["Eric Van Hensbergen" <ericvh gmail com>]

On 4/10/06, Ed Wilts <ewilts ewilts org> wrote:
>
> The obvious question is why?  What would this provide that the kernel
> and file systems don't already provide?
>

Well, kernel provides in-memory page cache, not local disk page cache.
 There is some ongoing remote file system local disk cache work being
done, but it applies primarily to AFS and NFS - not block-based
transports such as iSCSI and AOE.  The various cluster file systems
may provide something more akin to this, but again, this doesn't
really cover SAN technologies -- not in any sort of a generic way. 
Let me know if I'm missing something.

        -eric