On Wed, Jan 19, 2011 at 02:44:31PM -0200, Roberto Spadim wrote: > yes, a jornaling but using ssd first and sata after > it?s not raid feature... > it?s per disk filesystem feature... > we could implement jornaling in raid too... > but?s more inteligent (easy) at application level (filesystem) > you could write first at network (if it?s faster than sata) and after > at sata (if it?s slower than network) > > it?s not a raid feature... it?s a per device feature got it? > maybe a device (not raid..) for a cache division on devices > for example > > > /dev/sda (sata 1terabyte 100mb/s) > /dev/sdb (ssd 1gigabyte 1000mb/s) > > /dev/cache_a (a mix of sata and ssd with sata size 1terabyte, and > mixed speed (memory, ssd, sata)) > > cache_a device should know that > early reads/write should be writen to sdb > time in time it should sync at sda > > the same happens with memory (ram memory) but it?s volatille (diferent > than ssd that?s not volatille) > > /dev/sdb should be sync > /dev/sda should be async (since /dev/sdb make it safe to use async) > > > that?s you intention? i don?t know if linux have it, anyone know? I would use a physical ramdisk over a ssd but thats besides the point. They are still disk drives to the OS. Yes, I guess it would be similar to journaling but done in RAID itself. I don't believe it exists yet, thats why I'm asking if we could add support for this? -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
