[CentOS] large numbers of linux system user for postfix

Mon Nov 8 21:57:41 UTC 2010
John R Pierce <pierce at hogranch.com>

On 11/08/10 2:16 PM, nux at nux.ro wrote:
> 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).

indeed.   if half those 1000s of users do the typical lUser thing of 
checking their mail every minute, thats going to be a LOT of forks.