I have a directory (tomcat logs) which by accident ended up having close to a 7 million logs. Understandbly, while the files were there, things like ls took forever.  I cleared the files, but strangely when I first go to this directory and run ls, it still takes unreasonably long amount of time (20 seconds or so).  After I run it once, on the subsequent times it comes back instantly.  If I don't touch it for a while and run it again, it takes a long time again.. This behavior only started occurring after the directory was filled... Currently the directory contains 80 log files, no directories or symlinks. This behavior occurs only in this specific directory...  CentOS 6.
ls taking very long time after large number of files removed from directory
filesystems;ls;ext4