[anonacct37]

I also ran into spooky negative dentry issues. On a fleet of seemingly identical physical machines one machine would constantly check for files that didn't exist (iirc it was somehow part of nss and a quick Google search seems to confirm https://lwn.net/Articles/894098/ ).

I'm okayish at systems level debugging but I never figured that one out. It caused the kernel to use alot of memory. Arguable whether or not it impacted performance since it was a cache.