On 22 Mar 2018, at 11:37, Howard Chu <hyc(a)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.
> What I don't understand is why there is a difference between
filesystem and ramdisk? Is there any reason? The application (listed above) is not writing
on the lmdb, but just reading (using reading transaction). Thank you Luca
Using tmpfs is a waste of RAM. Just use LMDB on a regular filesystem and let the
system's pagecache manager take care of memory.
Got your point, but does make sense then to use a regular filesystem if the storage is a
“slow” non-SDD Hard drive?