[OpenAFS] Re: Afs User volume servers in VM's

Renata Maria Dart renata@slac.stanford.edu
Thu, 27 Oct 2011 11:11:19 -0700 (PDT)

Hi Jeff, thanks for your analysis and ideas on this issue.

On a similar note....we also experience random abuse on what we
call our RW servers.  We have segregated the RW copies of our commonly
used volumes, like root.cell, system and package utilities, etc,
from our user home directory space.  And we have RO servers
which only host readonly copies of those RW volumes.  This has
helped cut down on the situation when a batch user overwhelms
a server that contains a copy of root.cell.  But, even with
this segregation, every once in a while a user that maintains
some package space will do something to deplete the threads on
one of our RW servers.  Since there are cheap clones on the RW
servers, some portion of the user community will be affected
when this happens.  To further mitigate that we are considering
pulling out all of the cheap clones so that there is true
separation of the RO volumes and no chance for someone to
abuse the system related utilities.  I have been told that the
code will support the absence of cheap clones, but that
vos release will temporarily create one during its activity and
that the code is not in common use and not very well tested.
Is anyone else running without cheap clones?  Does anyone know
of any concrete problems running this way?