[OpenAFS] Some questions about AFS

Anders Magnusson ragge@ltu.se
Fri, 18 Jan 2008 15:45:07 +0100


Hi,

my name is Anders Magnusson and I work at Lule} University in Sweden.

We are currently evaluating different ways of handling data storage 
here, and one of the
products we have looked at is OpenAFS.  And the results are very promising.

I have some questions though.  I assume most of them can be found if 
searching around
but I'm getting grey hair when trying to find the answers, so I think it 
can be better to
just ask here :-)

Test environment has been Heimdal 1.0 + OpenAFS 1.4.5, servers Redhat 4 
(Dell 1950)
and Solaris 10 (Sun V880).  Clients was Redhat and for Windows (using 
1.5.28).


- What are the actual limitations on users/groups/volumes/sizes?  I'm 
interested in both
  practical and theoretical.  I have tested with 200k volumes/partition, 
which seems to
  work fine with the exception of that zapping volumes take 12 seconds each.
  I also added 200k users and 200k groups, and tested access groups with 
200k people
  in each, without any noticeable slowdown.  Quite impressive :-)   I 
don't know if or how
  any problem here should be noted.

- What are reasonable maximum on files/directory and 
mountpoints/directory? I tested by
  adding 64k mountpoints (volumes) in one directory, and accessing 
directories below did
  not become noticeably slower.  The only peculiarity I noted was that 
Windows explorer
  only showed the first 1000 entries, but I don't know if it is a bug in 
explorer or the AFS client.

- A few problems with the windows manager tools were also noted, it may 
be just me that
  haven't really understand how it all works :-)
    In the server manager; running salvager failed with the error messages:
       The AFS server manager was unable to perform the requested 
salvage operation.
       Error: unable to successfully read log file (0x0000422A)

  Also, moving volumes do not work, but I get no error message.  
``nothing happens''.

  The AFS account manager do not start for me at all, it just hangs with 
"Querying; please wait...".

I must say that we are all very impressed of how well it has worked so 
far!  Great!

-- Ragge