[OpenAFS] Re: Server disk operations speed

Andrew Deason adeason@sinenomine.net
Mon, 8 Apr 2013 13:00:43 -0500

On Mon, 8 Apr 2013 19:11:24 +0300 (EEST)
jukka.tuominen@finndesign.fi wrote:

> thank you for your responses. Before going through them in detail, I
> would just like to make a reality check. What kind of performance
> figures should one expect from an averagely working afs network
> (LAN/WAN)? Say, if you would duplicate roughly the 2000 files/300MB
> directory in your setup, what kind of rates do you get? That is, is
> 500-1000KB/s a reasonable starting point for optimization, not a
> magnitude or two higher?

That's not a transfer rate you need to "just accept"; I'm not sure if
I've seen a transfer rate that slow to the local machine.

If you want an example from unix... on an underpowered VM with no tuning:

$ find jukka -type f -print | wc -l
$ du -sh jukka
305M    jukka
$ time rsync -a jukka /afs/.localcell/lenny-1/foo3/jukka

real    0m18.777s
user    0m0.660s
sys     0m3.244s
$ time rsync -a 300mfile /afs/.localcell/lenny-1/foo3/300mfile

real    0m11.219s
user    0m0.416s
sys     0m3.196s
$ time rsync -a 300mfile 300mfile.2

real    0m5.435s
user    0m0.872s
sys     0m1.424s

That's still pretty slow, but faster than what you mentioned (16 MiB/s,
27 MiB/s, and 56 MiB/s). That's also a terrible benchmark since it's
only one trial and there are a million variables... but if you just
wanted an example, there is one.

Andrew Deason