[OpenAFS] vos move speed rates

Eric Chris Garrison ecgarris@iupui.edu
Tue, 12 Apr 2011 16:20:25 -0400

I've asked something similar before, but I could use some insight on how 
vos moves actually work.  I have a volume being vos move'd from one 
server to another right now, poking along in the range of about 15-20 
Mbit/s (on a Gigabit ethernet connection, on the same switch as the 
other server).  Other times, I've seen performance more like I expect, 
something around 300 Mbit/s.

It seems like smaller volumes move slower, larger ones move faster. 
  However this current large (200 GB, 300,000+ files) volume is moving 
slowly.  The faster-moving large volume is 280 GB, contains 18,000+ 
files (mostly larger video files).

Do the contents of a volume have an impact on the speed at which they 
are moved?  That is, if it's composed of many smaller files, does the 
metadata cause overhead, slowing the transfer down?  What other 
differences in the contents of a volume might make transfer speeds 
orders of magnitude different?  Are there any tricks to making slower 
volumes move more quickly?

Thanks again,

Indiana University
Research Storage