Samba Load Testing at Brunel University
Luke Kenneth Casson Leighton
lkcl at switchboard.net
Tue May 4 14:20:34 GMT 1999
your comments are extremely helpful.
yes, we recommend between 600 and 800k per client (we did 2 years ago for
up to 1.9.17, no info on whether this recommendation has changed or not).
yes, 2.0.x should give your users a significant performance increase:
numbers i remember off top-of-head are somewhere around 20% (anyone care
to elaborate / point to NetBench tests?)
what happens on the home directory servers? are those also samba?
On Wed, 5 May 1999, Peter Polkinghorne wrote:
> We wanted to find out how many PC clients our typical Sun server could
> support using Samba.
> In the past we have had a figure of 30 class room or 100 office clients
> using PC-NFS, being supported by a Sparc 2 in a shared ethernet environment.
> However we now have switched fast ethernet, Windows NT 4.0 clients and Sun
> Ultra servers using Samba. So how many clients will a server support in our
> new environment? The support here means supplying PC applications,
> home directories are a separate service with different sizing requirements.
> SET UP:
> System: Cedar - Ultra 5/270 with 192Mb of memory and 4 & 8 Gb SCSI disks
> and Fast Ethernet (full duplex).
> Software: Solaris 2.5.1 and Samba 1.9.18p10
> Role: All NT applications software supplied to NT 4.0 sp3 workstations.
> This machine already serves around 200 NT clients - admin users.
> We have around 450 NT clients on the campus - by map changes (NIS for those
> interested - we use NISgina), we moved them all in 3 stages to Cedar from the
> other 9 servers and observed the loading. The extra clients comprised of
> around 80 class room PCs and 170 or so office machines used by staff and
> post grads. The office machines are characterised by long login sessions
> and more diverse applications, whereas the classroom machines have short
> term use and tend to stick to word processing and web browsing.
> I tested the responsiveness by using a NT client and measured time to
> login and time to load Word 97. This enabled us to check whether the user
> perceived performance was acceptable.
> To the user point of view - service did not degrade by and large.
> My measured login and Word 97 startup times did not change.
> One or two users had difficulty connecting - possibly due to the resource
> intensive nature of the logins - each smbd took 7 secs CPU just to service
> the login - this is something we are investigating from the client side.
> I used Samba Snap - see ftp://ftp.brunel.ac.uk/cc/peter/samba/
> a little perl utility that condenses smbstatus output to observe usage:
> Connections Shares Files %shared memory (400k)
> Normal: 120 300 2,500 33%
> Peak: 344 600 6,300 69%
> The load on cedar did increase - the memory was not really adequate for the
> number of Samba processes - Swap space had to be raised to 460Mb.
> SAR indicated that the idle time went down to less than 20% for busy periods
> at peak test as opposed to 60% for normal load.
> The disks did not from SAR appear to be too heavily loaded, apart from for
> Network traffic at normal load is 300 k bytes a second (2.4 Mbps),
> whereas at peak it was 1000 k bytes a second (8 Mbps).
> Overall we were pleased that such a relatively lowly server could hand out
> PC applications to as many clients as well as that.
> We plan to use Sun Ultras for supporting upto 60 classroom and 400 office NT
> workstations per server and ensure there is a reasonable mix of office and
> classroom machines.
> OTHER THOUGHTS:
> Using Samba 2.0.X should improve performance (or so I have been lead to
> With Solaris 7 (and other OSs) the noatime type mount options would help.
> More memory would have helped cedar or may be we were hitting other barriers?
> Client behaviour is important.
> Can dig up more figures if useful ...
> | Peter Polkinghorne, Computer Centre, Brunel University, Uxbridge, UB8 3PH,|
> | Peter.Polkinghorne at brunel.ac.uk +44 1895 274000 x2561 UK |
<a href="mailto:lkcl at samba.org" > Luke Kenneth Casson Leighton </a>
<a href="http://www.cb1.com/~lkcl"> Samba and Network Development </a>
<a href="http://samba.org" > Samba Web site </a>
Luke Kenneth Casson Leighton | Direct Dial : (678) 443-6183
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