On Wed, Mar 14, 2012 at 02:33:25PM -0400, chetan loke wrote: > But you are not explaining why dm is not the right stack. Just because > it crashed when you tried doesn't mean it's not the right place. > flash-cache works, doesn't it? flash-cache's limitation is because > it's a dm-target or because it is using hashing or something else? > There are start-ups who are doing quite great with SSD-cache+dm. So > please stop kidding yourself. SATA-attached flash is not the only kind of flash out there you know. There is also PCIe-attached flash which is a wee bit faster (where wee is defined as multiple orders of magnitude --- SATA-attached SSD's typically have thousands of IOPS; Fusion I/O is shipping product today with hundreds of thousands of IOPS, and has demonstrated a billion IOPS early this year). And Fusion I/O isn't the only company shipping PCIe-attached flash products. Startups may be doing great on SSD's; you may want to accept the fact that there is stuff which is way, way, way better out there than SSD's which are available on the market *today*. And it's not like bache which is a new project. It's working code, just like flash cache is today. So it's not like it needs to justify its existence. Best regards, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html