Hi All ,

  Naive question ,need some help understanding these mirrors , I've read multiple docs and blogs online and on ECN but the mirror positions ,concept keeps bouncing off my head .I know that prior to 5874 Raid 1/5 occupied 2 (M1,M2)positions each and Raid 6 - one position .  5874 onwards all occupied one mirror position each . That's all I know .

Host I/O > Cache>Mirror>Tdev ? Is this how it works , is the mirror just a temp cache sort of device until the data is destaged to the actual tdevs ?

In simple terms , whats a mirror , why is it there , why won't the data go to the disks directly from cache ?

I would like to know how these work , an example prior 5874 and after will be great .

Edit :(Please attach : Timefinder clone/snap docs , my access is restricted and I can't get any )

Kind Regards

Message was edited by: asceticenergy