OneFS keeps the metadata in B-trees, which indicates there is no artificial limit...  The practical limit is what your system/application can handle. Say you need the parent directory to be fully listable at more or less "interactive" rates (tolerate few tens of seconds), I'd suggest to keep it smaller than 100,000 entries (metadata on disk) or 1 Mio entries (metadada on SSD). Where entries means files or subdirs.  Peter
Hi,  Does anyone know the subdirectories per directory limit for Isilon?  The release notes for the VNXe and VNX NAS state a hard limit of 65,533, but I can’t find a doc that states the limits for Isilon.  Thanks, Patrick. 
Isilon – Subdirectories Per Parent Directory Limit