Dear Sir, Thanks for your instant reply. I am not sure why I have a wrong title. I am asking for details of NVRAM journal replay anyway. The question is as ONTAP boots to finish the journal, if previously there are write I/Os and the data cached in DRAM has not been flushed to disk before the outage, how would WAFL do as it sees the journal? Where can it find the lost data, or I misunderstand something here? Thank you.
I apolpgize for being a little annoying, but this is what confused me. ONTAP does read journaled writes, but how does it complete the writes to disk?
If a few blocks are arrived at DRAM and write requests are journaled, and at the mean time power outage occurs so blocks in DRAM are lost. After ONTAP boots and wants to relpay the journaled writes, where can it find the lost blocks? Am I missing anything important?