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Conference turris::digital_unix

Title:DIGITAL UNIX(FORMERLY KNOWN AS DEC OSF/1)
Notice:Welcome to the Digital UNIX Conference
Moderator:SMURF::DENHAM
Created:Thu Mar 16 1995
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:10068
Total number of notes:35879

9276.0. "Mail Server Sizing" by NETRIX::"[email protected]" (Richard Quan) Tue Mar 25 1997 07:12

Melbourne University is looking to install a new mail server based on recent
purchase of a 4100
system running Digital Unix. At this stage they are looking to run PINE
supporting
approximately 30,000 users via telnet sessions.

Putting the intent to use the 4100 system aside, I am looking for general
sizing information and
issues in supporting such a user population; ie passwd files, number of telnet
sessions, mail 
requirements, ultimately with a view of sizing an appropriate system.

Most of the information for sizing that I have come accross seems
inappropriate (
being mainly for SAP, Oracle etc but nothing on mail servers.

/Richard
Melbourne CSF
[Posted by WWW Notes gateway]
T.RTitleUserPersonal
Name		DateLines
9276.1telnet limitationsSMURF::DUSTINTue Mar 25 1997 09:2412
    You won't be able to support more than around 2000 simultaneous
    telnet users, due to the high overhead of the single-character
    processing between telnetd and the shell.
    
    If you have 30,000 accounts, that should work ok as long as not
    more than a couple thousand log in at once..
    
    There may be other problem areas as well, this only covers the
    telnet part of the equation.
    
    John
9276.2Re: Mail Server SizingQUABBI::"[email protected]"Ong Beng HuiWed Mar 26 1997 02:2337
>Melbourne University is looking to install a new mail server based on recent
>purchase of a 4100
>system running Digital Unix. At this stage they are looking to run PINE
>supporting
>approximately 30,000 users via telnet sessions.

I have a similar problem. I have a customer (ISP) who is looking for a
internet mail server architecture to scale to 300K users. The only
thing I can think of is InterMail (http://www.software.com)

30K seems okay at the moment. My customer is now running a pair
of 4100 with ASE supporting 50K users. Things to look out for will be
user account, disk storage, network, and the type of mail software.

My customer is running the usual sendmail. This is a problem
because the mail spool by default is a single directory
/var/spool/mail. Performance is a problem with linear search for
directory lookup.

High performance controller might offset the problem.

The current Digital UNIX has a limitation of 16bit UID. This limit 
the maximum user onboard to 64K. Personally, I think it is a serious
limitation with the processing power of AlphaServers.

As mentioned, you gonna have problem with telnet session.

>Putting the intent to use the 4100 system aside, I am looking for general
>sizing information and
>issues in supporting such a user population; ie passwd files, number of telnet
>sessions, mail 
>requirements, ultimately with a view of sizing an appropriate system.

As you mentioned such information seems pretty rare.

[posted by Notes-News gateway]
9276.3KITCHE::schottEric R. Schott USG Product ManagementWed Mar 26 1997 21:0911
My understanding is that sendmail can be configured to deliver mail
to the user home directory rather than /var/spool/mail/username

the UID extensions are coming in V4.0d, with some restrictions (to be
release noted).   If you run a V4.0 os base, and install patches, you
should be fine.

You should state what is the concurrent login load on the system per
.1.
9276.4No of Concurrent UsersNETRIX::"[email protected]"Richard QuanSat Apr 05 1997 00:444
They're looking to have between 3000 - 4000 concurrent users.

/Rich
[Posted by WWW Notes gateway]