smbd load of large numbers of client

William Jojo jojowil at
Tue Feb 25 20:56:10 GMT 2003

well here's the thing. Samba does a great job of managing the PC's and
their romaing profiles. Two things you need to consider that I've found in
our 800 machine environment.

We had a problem with the number of small files and server
performance. This is not Samba's fault in any way. We have 5300 users and
they are spread over 8 filesystems with symlinks from /home. Some things
you can do is mod the uid by 8 and that's the filesystem they fall into.

anyway we had 8 million total student files. i just finished removing 2.4
million in IE and NS cache. Now things are much much smoother than the
last few weeks at login time.

that's number one. number two is build a fast i/o infrastructure. that
means both network and disk. we use 10k 36GB SSA disks from IBM. they're
*fast*. Microsofts use of roaming profiles is interesting in theory, but
the practical application of having one server do everything is an issue
especially when users cannot manage their profiles properly.

roaming profiles can reduce a $125,000 RS/6000 to a doorstop if you're not
careful. We are branching out and having one server for served software,
one for H: (homes) space and one for profiles (on order). The new 630 with
4-Power4+ cpus at 1.45GHz each and 8GB memory for $40,000 is going to do
nicely for us. (of course i have a really nice director who like to give
me money)

I'm in *NO* way indicating you will need to do this. We *need* to because
of what we call the "top of the hour" effect where students log off to go
to another class and login someplace else. this creates a tremendous
amount of i/o for about 20 minutes - 10 of to 10 past the hour.

our current server IBM-RS/6000-6H1 with 6 cpus and 6 GB memory can handle
the punishment of 550 workstations all logging in at the same time. I
cannot say for 800 since not all classrooms are full. Hope that helps.

BTW, we are a community college with 11,000 students and 5300 of which
actively use our 800 XP based PCs.

Keep up the great work Samba Team!!!


On Tue, 25 Feb 2003, Richard Sharpe wrote:

> Hi,
> Is anyone running larges numbers of clients against Samba servers? Here I 
> am thinking of 1000+ clients, and wanting to get a feel for the load of 
> 1000+ smbds.
> I already know that at least with the 2.2.x base, smbd maintains 29 open 
> file descriptors before it opens any files for users, but am wondering 
> about the memory load (which should not be too bad with copy-on-write on 
> modern UNIXen) and context switch load?
> Regards
> -----
> Richard Sharpe, rsharpe[at], rsharpe[at], 
> sharpe[at],

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