[OpenAFS] Debugging AFS sluggishness on MacOS 10.5.7?
Felix Frank
Felix.Frank@Desy.de
Tue, 30 Jun 2009 07:37:57 +0200
> Another tidbit that is either hopelessly banal because I don't
> understand how AFS works, or really important: WRITING to the same AFS
> directory works fine. I copy the file from the directory to my local
> disk and it takes 4 minutes; I delete the file from the remote disk and
> write it there from my local disk and it takes 30 seconds.
Just a side remark: If the file is smaller than your cache, then this is
probably the cache manager writing to the cache, which is supposed to be
fast. I'd expect a rather sharp corner in the write performance curve as
soon as your amount of data surpasses disk cache size.
On Linux, I have also found the memcache to make more balanced and
efficient overall use of your bandwidth when transferring bulk data.
I haven't thoroughly investigated random access to small files, but the
expectation is that a large-ish disk cache is at an advantage for that.
Cheers
- Felix