db servers separate hardware

[Stephen Joyce]

Semi-related question:

What category of hardware are most cells using for file and/or db servers?
On that hardware, what kind of performance do you see for real-world file
access? (yes, I know this is not AFS' strongpoint).

We're running 3 file/db servers, all Sun Enterprise 250's (at least
256MB ram, 440Mhz cpu, 400GB raids). A test on an Ultra 10/440 client
yields an average of 2.45 MB/sec read on a 80 MB file. Writing the same
file back yielded an average rate of 3.24 MB/sec (not quite scientific, as 
other users were accessing files; more a seat-of-the-pants comparison).

FWIW: I'm running with:
parm /usr/afs/bin/fileserver -L -p 64 -rxpck 2000 -udpsize 1048576
parm /usr/afs/bin/volserver -udpsize 1048576 -sleep 1/15

Is anyone seeing substantially better (or worse) performance?

Cheers,
Stephen
--
Stephen Joyce
Systems Administrator                                            P A N I C
Physics & Astronomy Department                         Physics & Astronomy
University of North Carolina at Chapel Hill         Network Infrastructure
voice: (919) 962-7214                                        and Computing
fax: (919) 962-0480                               http://www.panic.unc.edu

On Wed, 13 Jun 2001, Antoine Verheijen wrote:

> Actually, I have found that the performance of DB services can suffer
> when you do this. File server functions run at a higher priority than
> the DB functions so that the machine will respond to file services
> before it responds to DB services. This can slow things noticably if
> the DBs are locked for synchinization and the file services happen to
> be very active.
> 
> On Wed, Jun 13, 2001 at 02:32:35PM -0400, John W. Sopko Jr. wrote:
> > We have 3 large db/file server machines, (200GB each), and have
> > run db/file servers on the same machines for over 5 years without
> > any issues. The admin guide implies if you have 3 or fewer machines
> > run them both as a db and file servers:
> > 
> > "A simple file server machine runs only the server processes that store
> > and deliver AFS files to client machines, monitor process status, and
> > pick up binaries and configuration files from the cell's binary
> > distribution and system control machines. 
> > 
> > In general, only cells with more than three server machines need to run
> > simple file server machines. In cells with three or fewer machines, all
> > of them are usually database server machines (to benefit from
> > replicating the administrative databases); "
> > 
> > The admin gu
> > 
> > 
> > Patty OReilly wrote:
> > > 
> > > Management wants to consolidate services where possible at our site. We
> > > have always adhered to the recommended practice of keeping our Database
> > > servers running vlserver, kaserver, ptserver and buserver on separate
> > > machines from our Fileservers. Now they want us to consolidate these
> > > services and run all AFS server processes on our Fileservers.
> > > 
> > > Does anyone have any information pro or con that could help us decide
> > > whether consolidation of Fileservers and DBservers would be successful?
> > > 
> > > --patty
> > 
> > -- 
> > John W. Sopko Jr.               University of North Carolina
> > email: sopko@cs.unc.edu         Computer Science Dept., CB 3175
> > Phone: 919-962-1844             Sitterson Hall; Room 135
> > Fax:   919-962-1799             Chapel Hill, NC 27599-3175
> 
> -- 
> 
> -----------------------------------------------------------------------
> Antoine Verheijen                  Email: antoine.verheijen@ualberta.ca
> CNS Network Services               Phone: (780) 492-9312
> University of Alberta              Fax:   (780) 492-1729
>