CentOS - Nov 2010 - large numbers of linux system user for postfix

hello,

i need to setup a mail server with postfix + dovecot + webmin +
virtualmin + virtual user with linux system user. the virtual user may
reach to thousands user from several hundreds virtual domains.

what i concern is large numbers of linux system user which used in
these setup, is it good or bad?
maybe somebody would share their experience about this setup ?

any links would be good.

postfix 2.6.7
dovecot 2.0.6
centos 5.x
webmin + virtualmin


thank you.

-- 
http://blog.rizahnst.org

On 08/11/10 08:30, ahmad riza h nst wrote:
> hello,
>
> i need to setup a mail server with postfix + dovecot + webmin +
> virtualmin + virtual user with linux system user. the virtual user may
> reach to thousands user from several hundreds virtual domains.
>
> what i concern is large numbers of linux system user which used in
> these setup, is it good or bad?
> maybe somebody would share their experience about this setup ?
>
> any links would be good.
>
> postfix 2.6.7
> dovecot 2.0.6
> centos 5.x
> webmin + virtualmin
>
>
> thank you.
>
Other that "centos 5.x", none of the rest is shipped by CentOS so
you're
unlikely to get much help here.

Also, please don't cross post the same question to multiple lists - you 
have an active thread on the postfix users list and most postfix users 
on this list will also be subscribed there too.

On 8/11/10 7:30 PM, ahmad riza h nst wrote:
> hello,
> 
> i need to setup a mail server with postfix + dovecot + webmin +
> virtualmin + virtual user with linux system user. the virtual user
> may reach to thousands user from several hundreds virtual domains.
That shouldn't be a problem.  Postfix has had support for this for
well over a decade.
> what i concern is large numbers of linux system user which used in
> these setup, is it good or bad?
Virtual users with a Postfix/Dovecot installation does not equate to
real Linux/shell accounts.  If the only service being provided is
mail, then there's no reason to create real accounts.
> maybe somebody would share their experience about this setup ?
> 
> any links would be good.
> 
> postfix 2.6.7
> dovecot 2.0.6
> centos 5.x
Is there any particular reason you've chosen these versions?  That is,
are there specific functions which these versions provide that are not
in prior versions?

I ask because I'm running these versions in CentOS 5.x:

postfix-2.3.3-2.1.el5_2.i386
dovecot-1.0.7-7.el5.i386

If the only concern is security updates, these are backported to the
current versions in CentOS.
> webmin + virtualmin
I've had no experience with either of these as I edit the config files
with a text editor.


Regards,
Ben

-- 
Ben McGinnes  http://www.adversary.org/  Twitter: benmcginnes
    Systems Administrator, Writer, ICT Consultant
Encrypted email preferred - primary OpenPGP/GPG key: 0xA04AE313
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x371AC5BFA04AE313


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On Mon, Nov 8, 2010 at 6:42 PM, Ben McGinnes <ben at adversary.org>
wrote:
> On 8/11/10 7:30 PM, ahmad riza h nst wrote:
>> hello,
>>
>> i need to setup a mail server with postfix + dovecot + webmin +
>> virtualmin + virtual user with linux system user. the virtual user
>> may reach to thousands user from several hundreds virtual domains.
>
> That shouldn't be a problem. ?Postfix has had support for this for
> well over a decade.
>
>> what i concern is large numbers of linux system user which used in
>> these setup, is it good or bad?
>
> Virtual users with a Postfix/Dovecot installation does not equate to
> real Linux/shell accounts. ?If the only service being provided is
> mail, then there's no reason to create real accounts.
>
Ben,

the problem is we would use webmin + virtualmin as an interface for
costumers to manage their domain (mainly emails) on the server and
virtualmin don't use/support mysql + vpopmail yet, at least that what
i understand at this moment.

virtualmin choose to use unix system user with postfix, so if i create
an email then it create one unix system user too, this is what i'm
concern, since i don't have any information about what happen to
linux/centos if these unix system user growing bigger and bigger to
reach some thousands users for an example.
>> maybe somebody would share their experience about this setup ?
>>
>> any links would be good.
>>
>> postfix 2.6.7
>> dovecot 2.0.6
>> centos 5.x
>
> Is there any particular reason you've chosen these versions? ?That is,
> are there specific functions which these versions provide that are not
> in prior versions?
>
> I ask because I'm running these versions in CentOS 5.x:
>
> postfix-2.3.3-2.1.el5_2.i386
> dovecot-1.0.7-7.el5.i386
>
> If the only concern is security updates, these are backported to the
> current versions in CentOS.
no particular reason, i just new to postfix, currently i'm qmail +
vpopmail admin.
i read on postfix and dovecot website about latest stable release and
i installed from source :)
i know that centos have postfix + dovecot + mysql as a rpm package.
>
>> webmin + virtualmin
>
> I've had no experience with either of these as I edit the config files
> with a text editor.
>
these webmin + virtualmin mainly for user interface to manage their
domain on the server (just like control panel on hosting server)
>
> Regards,
> Ben
>
> --
> Ben McGinnes ?http://www.adversary.org/ ?Twitter: benmcginnes
> ? ?Systems Administrator, Writer, ICT Consultant
> Encrypted email preferred - primary OpenPGP/GPG key: 0xA04AE313
> http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x371AC5BFA04AE313
>
>
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>
>


-- 
http://blog.rizahnst.org

On Nov 8, 2010, at 2:30 AM, ahmad riza h nst wrote:
> hello,
> 
> i need to setup a mail server with postfix + dovecot + webmin +
> virtualmin + virtual user with linux system user. the virtual user may
> reach to thousands user from several hundreds virtual domains.
> 
> what i concern is large numbers of linux system user which used in
> these setup, is it good or bad?
> maybe somebody would share their experience about this setup ?
> 
> any links would be good.
> 
> postfix 2.6.7
> dovecot 2.0.6
> centos 5.x
> webmin + virtualmin
> 
> 
> thank you.
> 
> -- 
> http://blog.rizahnst.org
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
I run Postfix 2.6.7 in a similar fashion (virtual domains/users/etc) and it
works fine on CentOS 5.5 (even with SELinux enabled). Dovecot on the other hand
threw up some errors in /var/log/audit/audit.log so I had to make a custom
SELinux module to get it to work properly. Other than that you should be set.

-Dan

ahmad riza h nst writes:
> hello,
> 
> i need to setup a mail server with postfix + dovecot + webmin +
> virtualmin + virtual user with linux system user. the virtual user may
> reach to thousands user from several hundreds virtual domains.
> 
> what i concern is large numbers of linux system user which used in
> these setup, is it good or bad?
The large number of system users should not be a problem. Might have been an 
issue with Linux 2.4 (2^16=65536 max users), but Linux 2.6 can handle a LOT 
(2^32=4294967296)[1].

I'd be more worried of the stress this number of users can inflict on a 
machine (CPU, memory, I/O etc).

[1] - http://en.wikipedia.org/wiki/Linux_kernel

--
Nux!
www.nux.ro