samba - Oct 1998 - Performance (and other) problems

Over the last summer we took our home dir / applications servers for the
330 Win95 PCs that they service and attempted to replace them with a
single AlphaServer 8200 (Digital Unix (OSF/1), Samba, 4GB RAM, 2x525Mhz cpus).

The results were *not* good.

In fact, it was terrible.  We have since gone back to using the original 3
machines.  My suspision is that the clients are making way too many
demands of the servers.  In particular, we serve the applications (Office,
WP, etc.) to the clients from shares on the servers.  These "application
servers" are constantly busy, especially with CPU time.  When loading all
this onto one server, it just about fell over and died.

I have noticed that the problem still remains, although it's a lot less
than before.  We also have other problems, the foremost being that Samba
does not appear to answer logon requests at certain times.  It appears to
be random as I haven't found a pattern yet.  The logon servers are the
application servers, so I suspect that the servers are too busy to answer
logon requests.  I don't know...

I have reduced the amount of CPU usage by doing things like "lpq command
echo 'no entries'" and the like, but this is a bandaid solution.  I
have
also recompiled Samba with the highest optimizations that DEC cc provides.
I want to get all those clients on my 8200.

This 8200 has 5 100Mb/FD network ports, which eventually get filtered down
to 10Mbps to the clients with switched hubs, so I can't see a network
problem.  But networking isn't my strongest field.


I would like some coorespondence with other admins who have a similar
setup to mine and trade some ideas.  I'm really in a bind here and any
info would be helpful, I think.

Thanks.

Rob Naccarato           "Civilized men are more discourteous than savages
Sys Admin               because they know they can be impolite without
Sheridan College        having their skulls split, as a general thing."
Oakville, Ont. Canada                      - Robert E. Howard

You wrote:
| Over the last summer we took our home dir / applications servers for
the
| 330 Win95 PCs that they service and attempted to replace them with a
| single AlphaServer 8200 (Digital Unix (OSF/1), Samba, 4GB RAM,
2x525Mhz cpus).
| The results were *not* good

	I can help, a bit:  I have a small performance model I use
	for sizing, and can make a back-of-envelope estimate based
	on
		cpu type and number
		bus type
		number of ethernets and speed
		number of scsi controllers
		number of disks on each of the above controllers.

	Can you send me (and others who want to help) that sort of info?
	It's genuinely unusual that Samba is bottlenecking on cpu:
	most people have far more than they do disk bandwidth

	I promise to report back to the group.

--dave
-- 
David Collier-Brown,  | Always do right. This will gratify some people
185 Ellerslie Ave.,   | and astonish the rest.        -- Mark Twain
Willowdale, Ontario   | davecb@hobbes.ss.org, canada.sun.com
N2M 1Y3. 416-223-8968 | http://java.science.yorku.ca/~davecb