> reports from users about "slowness" and "brief hangs" (10s-1m) even
> when
> running simple commands like "ls", this only seems to happen when
> they've got CVMFS directories in their path.
I would imagine that the shell, when searching for (say) ls uses the
directories in the path. Since ls is in /bin, then the first directory
in the path should be /bin. The shell will then find ls in the first
PATH entry, and it won't look further and so will not need to look in
the CVMFS directories. So it should be faster, perhaps...
> Possibly related we see
> that ls'ing a directory in CVMFS is slow the first time but much
> quicker after that, which is to be expected,
Yes, I think it is.
> but if it's not accessed for about an hour or so (though sometimes
> less) the next
> access is again slow. As though it's dropped out of the cache or
> something.
I've never really noticed the "hour or so effect", but I can see what
you mean. I'm thinking about autofs, which CVMFS uses (or did use).
Perhaps, after a long time, it "disconnects". Or I'm thinking cache size
or timeouts and things like that...
Cheers,
Ste
|