On Mon 25 Oct, 1999, "Luke Gain" luke@erinet.com wrote:
one thing I found to be a big win is to make sure all the filenames are 12 characters or less. evidentally, the netapp only caches names that are <12 characters long. so if the name is >12 characters it takes a disk-op to read the directory.
I expect it'll interact with your operating system, too (or this may actually be the sole cause.) Eg. Solaris puts namei lookup results in the DNLC (directory name lookup cache) only if they're under a certain size (vmstat -s shows these as "toolong"), so if you've got long directory paths you would expect to see a problem not dissimilar to the one you describe. On the subject of the DNLC, beware of making it too big as that has been bad for performance too.
("classic" BSD sets this "toolong" constant NCHNAMLEN at 31. FreeBSD-current seems to have done away with it.)
James.