Re: System UICs

Lawrence D'Oliveiro schrieb am 07.06.2024 um 04:32:

As I recall, on VMS, SYSPRV privilege was effectively granted to any
process whose UIC was in a “system” group. By default this was all UICs
from [1,*] to [10,*] (octal), but I recall docs saying the upper limit was
configurable.

SYSGEN> help sys_para maxsysgroup
Sys_Parameters
   MAXSYSGROUP
        MAXSYSGROUP sets the highest value that a group number can have
        and still be classified as a system UIC group number. Note that
        the specification is not in octal unless preceded by the %O radix
        indicator. This parameter is normally left at 8 (10 octal).
        MAXSYSGROUP is a DYNAMIC parameter.

I also recall that, when you woke up the login prompt, the LOGINOUT
process was created running under UIC [10,40]. I wonder if this was chosen
to ensure that sysadmins would never lower the upper bound below 10 octal,
they could only raise it? Did the UIC [10,40] have any other significance?
Perhaps something from RSX-11 days?

Here, LOGINOUT is running under [1,4] (usually assigned to the SYSTEM account).
Hans.