topic Re: Maximum UID and GID in Operating System - Linux

Maximum UID and GID

SGK — Mon, 17 Jul 2006 05:32:38 GMT

Hi,

What is maximum number for UID and GID for Redhat Linux and OpenBSD?

TIA.

Re: Maximum UID and GID

Alexander Chuzhoy — Mon, 17 Jul 2006 06:52:07 GMT

Maximum recommended is: 65535
But the maximum allowable uid/gid is:
4294967295

Re: Maximum UID and GID

Alexander Chuzhoy — Mon, 17 Jul 2006 06:53:30 GMT

True for Redhat and FreeBSD.

Re: Maximum UID and GID

SGK — Mon, 17 Jul 2006 07:12:25 GMT

Is it same for OpenBSD?

Re: Maximum UID and GID

Alexander Chuzhoy — Mon, 17 Jul 2006 07:20:31 GMT

Never worked on this distribution.
I suggest you to create a user there and to play with it:
first try to assign it the mentioned UID - in case it works -try a bigger one.
Anyway - I wouldn't recommend you to work with something that isn't recommended by the system (obviously).
Cheers.

Re: Maximum UID and GID

Steven E. Protter — Mon, 17 Jul 2006 07:23:52 GMT

Shalom,

I believe this is a System V convention.

Its time to test it though, it will do no harm creating a dummy user and editing /etc/passwd and /etc/group for test purposes.

SEP

Re: Maximum UID and GID

SGK — Mon, 17 Jul 2006 07:33:35 GMT

Hi,

I think the Maximum UID/GID for OpenBSD is 2147483647. I tried the following steps in OpenBSD:

# groupadd -g 42949672950 testgrp
# more /etc/group
testgrp:*:2147483647:

# useradd -g testgrp -u 42949672950 testusr
# more /etc/passwd
testusr:*:2147483647:2147483647::/home/testusr:/bin/csh

Based on the above result, I guess its 2147483647.

Correct?

Re: Maximum UID and GID

Alexander Chuzhoy — Mon, 17 Jul 2006 08:24:50 GMT

I'd assume so.

Best regards.

Re: Maximum UID and GID

Stuart Browne — Mon, 17 Jul 2006 18:07:55 GMT

*chuckles* they signed the longint :P

Re: Maximum UID and GID

Ryan Goh — Mon, 24 Jul 2006 21:37:27 GMT

In Red Hat Enterprise Linux 2.1 and later versions the Linux kernel supports 32 bit limits for the UID and GID. The UID and GID are stored internally as signed integer values, so there are 31 bits available to store UID's and GID's. This results in a system limit of 2,147,483,648.

For full info, go to http://kbase.redhat.com/faq/FAQ_80_6231.shtm