I just found this at the DEC Documentation Web site
<
http://www.unix.digital.com/faqs/publications/pub_page/V40D_DOCS.HTM> under
"Release Notes"
<
http://www.unix.digital.com/faqs/publications/base_doc/DOCUMENTATION/V40D_H
TML/AQTLMCTE/TITLE.HTM>.
Thank you to everybody who helped.
1.2 Maximum Number of UIDs and GIDs
On UNIX systems, each user is known to the system by a unique number
called a user identifier (UID). The system also knows each user group by a
unique number called a group identifier (GID). The system uses these numbers
to track user file access permissions and group privileges and to collect
user accounting statistics and information.
With DIGITAL UNIX Version 4.0D, the maximum number of UIDs and GIDs
allowed increases from 65,535 (16 bits) to 2,147,483,647 (31 bits). Note
that this increase does not mean that 2.14 million users can simultaneously
log onto a system; rather, it means that 2,147,483,647 user and group
identifiers are available. The maximum number of users that can be logged on
is determined by the available system resources.
To preserve strict binary compatibility with legacy applications,
the new limits are not enabled by default in Version 4.0D. See Appendix C
for instructions about how to enable extended UIDs and GIDs and a list of
restrictions that apply to the implementation of the new limits.
> ----------
> From: John Losey[SMTP:JOHLOS_at_HBSI.COM]
> Sent: Monday, November 16, 1998 11:00 AM
> To: OSF Managers Group
> Subject: SUMMARY: Maximum number of groups under DU4.0D
>
> Thanks to Mike D Cross <crossmd_at_mh.uk.sbphrd.com> & Alan
> <alan_at_nabeth.cxo.dec.com> for their quick replies.
>
> Mike reminded me that problems arise if a particular user belongs to 16+
> groups and Alan said:
> Probably 65536, though some applications may use the
> group id as a signed short, making it 32,767. Where
> recent versions allow the UID to use a 32 bit integer,
> the group ID may have inherited the same support. Limits,
> where documented, are usually in the release notes. Just
> because the group ID can go this high, doesn't mean anybody
> has ever tested it there.
>
> Thank you both for your quick replies.
>
> John
>
Received on Mon Nov 16 1998 - 19:19:36 NZDT