ID Numbering in Group and Passwd

[Robin Laing]

James Wilkinson wrote:
> Robin Laing wrote:
> 
>>Using the reverse method for groups would even remove the necessity to 
>>set GID_MIN unless there are 40,000 unique groups which I find really 
>>impossible.
> 
> 
> With the Red Hat standard "user private groups" (one group per user),
> all you need is 40000 users.
> 
> In a big university or company, that's not impossible.
> 
> http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/ref-guide/s1-users-groups-private-groups.html
> 
> James.
> 

I wasn't talking about user groups.  I was talking about groups that 
don't have specific users.  In my case it is shared groups for family 
files, groups for shared multimedia files that I don't want my kids to 
view etc.

To explain further.

Users start at 500 as they do now.  If I want to add a group such as 
mpaa-R for R rated DVD's that I stored on my system, they would start 
at 60,000 if I had GID_MAX set to 60,000.

Lets say I have 12 users and 11 extra groups.  This means that the 
USER GID's are 500-512  The extra groups are 59,989-60,000.

This means that there could be upto 59,489 total users using RH's 
UID=GID concept before a collision unless more groups were added.  No 
real need to manually select GID's or even to change limits if the 
defaults are set properly.

All UID/GID combos are still in order if the defaults work as expected.

Does this clear up some of the mud now? :)

Robin.