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Re: LMDB on Ramdisk (tmpfs)



Luca Foppiano wrote:


On 22 Mar 2018, at 11:37, Howard Chu <hyc@symas.com> wrote:

According to my understanding the memory is dirty when 1)there are open transactions, 2) the data has not been written back to the filesystem

Your understanding is incorrect. Dirty pages remain dirty until they are written to stable storage (e.g., disk). A tmpfs/RAMdisk has no stable storage, all of its pages reside only in RAM. That's the point of a RAMdisk.

Ok, thanks for have it clarified. I was just “hoping” LMDB would have not notice the type of storage was syncing to.

And LMDB doesn't. The behavior you see is due to how tmpfs works.

--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/