[Lustre-discuss] Performance issues in directories after large number of I/O operations on small files.

[Sebastian Gutierrez]

Hello
I have a user that keeps having issues after using a directory and
performing quite a number of I/O operations on the folder.

If he moves delete creates files in a directory on his luster working
directory the directory eventually gets unmanageably slow.  He is
working with a large number of small files.
Here is a example of a copied directory that shows the directory
metadata much smaller but has the exact same data in it.

drwxr-sr-x  3 user group     4096 Dec  3 17:26 StatisticsQualScore
drwxr-sr-x  3 user group 12623872 Dec  3 15:59 StatisticsQualScore_old

After a copy of the directory the directory speeds improve.

Is this happening because of a LRU sizing issue or could there be
something else that could be causing this?  We currently have a work
around but I would like to have a better understanding of this and
possible solution or option I can implement.

Thank you
Sebastian