On Sun Solaris, the message queue parameters are modified by editing the file /etc/system and then rebooting the system. For example, the parameter MSGMNI can be changed from the default value (usually 50) to 100 by adding the line "set msgsys:msginfo_msgmni = 100" to /etc/system.

On most Linux systems, the default limit for message queues is 16 which supports only 16 users. The limit can be increased by adding the line "kernel.msgmni = limit" to the text file /etc/sysctl.conf where "limit" is the new limit value. The /etc/sysctl.conf file can be modified using any text editor. For example, adding the line "kernel.msgmni = 72" would set the limit to 72 after the next system reboot. The current limit can be increased by using the command "/sbin/sysctl -w kernel.msgmni=72", but the new value will be lost after the next reboot unless the /etc/sysctl.conf file is modified. The command "ipcs -lq" displays the current message queue limits.

Some of the message queue parameters can be set in the "scoadmin" Hardware/Kernel Manager, but others can only be configured by using the idtune utility. For example, the command "/etc/conf/bin/idtune MSGMNI 100" would set the maximum number of message queues to 100. Since each user and phantom port requires each own message queue, a maximum of 100 would be adequate for approximately 100 users (more may be needed by the operating system and other software products). After changing a message queue parameter, the kernel must relinked using "scoadmin" and the system must be rebooted. Other message queue parameters may need to be changed as described in the UniBasic Reference Manual or the dL4 Installation and Configuration Guide for Unix. If a message queue parameter has been changed from the default value, its current value can be found in the /etc/conf/cf.d/stune file. Please refer to your SCO manual for a detailed description for idtune.

Current Linux systems require version 3.7.2 or later of the Passport software. Current versions of UniBasic or dL4 require Passport 4.1 or later.

SCO OpenServer 5 requires passport version 3.5.1 or later.

Related Article: Technical News, April 22, 1996: Passport 3.5.1

The makeosn utility is part of Passport For Unix and Passport For Windows effective release 3.6 and 1.4, respectively. It is no longer distributed with UniBasic, effective UniBasic version 6.

Before proceeding, please be certain that there are no dL4, UniBasic, or IQ users on your system before removing current license.

Kill the running passport daemon and remove the /etc/DCI/license file. Restart the passport daemon by running /etc/DCI/passport.cmd after removing the /etc/DCI/license file. Remember to acquire and enter a new SSN prior to using dL4, UniBasic, or IQ.

On most Unix systems, using the "-a" option with cpio alters the "change time" on each file processed. Do not use the "-a" option when backing up files in the /etc/DCI directory or skip the /etc/DCI directory when performing backups.

This problem can be avoided by using a hardware passport device.

This error is reported by the operating system when the message queue buffers are full. Although it is possible that the system message queue buffer size was set too low, the more likely cause is unread messages. A common programming error is not to clear system signals after an INPUT TIM statement for an IRIS program. This error can also be reported when UniBasic, dL4, or IQ are first started if the system doesn't have a sufficient number of message queues (MSGMNI) allocated.