On 04/05/14 19:00, Howard Chu wrote:
Kristian Amlie wrote:
It turns out that LMDB does not work correctly on the AUFS filesystem. Is this known?
No, thanks for that info. The filesystem types we tested are listed here http://symas.com/mdb/microbench/july/#sec11
After more investigation, I have found that it takes a very special set of circumstances to trigger the bug. Basically you have to mount the same writable directory branch onto two mount points using AUFS, and then access the database separately from each mount point. This is most likely a very uncommon setup (*), and I don't think perfect thread synchronization can be expected from it.
So in short, this is a non-issue, but at least now we know why! :-)
(*) Uncommon, but not unheard of: The "schroot" tool uses this when you use the "union-type=aufs" option.