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SCO Openserver 5.0.5, how do I increase wait semaphores

Posted on 2002-06-13
Medium Priority
Last Modified: 2013-12-16
Restarting the server I get the warning: "SERVER: Warning: Only 60 wait semaphores are available" this error happens during a buzzy day when users try to login.

So how do I increase the wait semaphores?

Please keep it simple, I'm a user that have responsibility for computers and servers in a small company. We don't have a IT staff so I'm it.
thanks for any help
Question by:nilsc
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LVL 38

Expert Comment

ID: 7077029
login as root (or su as root):

type in: scoadmin

the follow the menu, to change the kernal parameter, then relink the kernal and reboot the system.
LVL 38

Expert Comment

ID: 7077042
I don't have a SCO system with me at the moment, if you want more details, please post the option avaiable on the screen when after you type in scoadmin.
LVL 38

Expert Comment

ID: 7077310
Here's more infor about the parameter change:

   Try to run scoadmin in command line mode:
   scoadmin system tun <enter>

   You need to cahnge SHMMNI, SEMMNI and SHMSEG values
just go throuht all the value, for the one you don't want to change, press <enter>, when you see the value you want to change, type in the new value.

   remember to re-link the kernel after it is done.

Here're some infor about the three parameters:

    For servers providing RS-232 services only:

    Section       Variable    1-16 User   17-32 User   33-64 User
    Semaphores    SEMMNI      + 20        + 40         + 80
    Semaphores    SEMMNU      + 40        + 80         + 160
    Shared Data   SHMMNI      + 20        + 40         + 80

For servers providing LAN and RS-232 service:

    Section        Variable   1-16 User   17-32 User   33-64 User
    Semaphores     SEMMNI     + 20        + 40         + 80
    Semaphores     SEMMNU     + 40        + 80         + 160
    Shared Data    SHMMNI     + 20        + 40         + 80
    Streams Data   NSTREAM    + 20        + 40         + 80
    Streams Data   NUMTIM     + 20        + 40         + 80



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Author Comment

ID: 7078060
Thank You,
  I logged on as root and tried the scoadmin system tun command, the only options I have in system are
Cron Manager, International Settings Manager, MOTD Manager, System Defaults Manager, System Shutdown Manager, System Startup Manager, System Time Manager, Terminal Manager, Logs, and Security.

Is it possible that this could be in a different place? for example if I go into /etc/conf/cf.d and type ./configure -g SHMMAX and the use pwd the path is changed to /var/opt/K/SCO/likn/1.1.1Eb/etc/conf/cf.d (is this normal?) I get no info, if I try the ./configure ... again in this directory I get a core dump.

I know I got a little of track, but I'm trying to figure out if there is another way to get to those settings

Thanks again,
LVL 38

Expert Comment

ID: 7078735
Hi nilsc,

   I just have a look at a SCO Openserver 5.0.5 at home. Here's exactly what you need to do:

   login as root, from a text mode screen (<Alt> F1), if you don't know how, just boot up the system to single use mode. (please forget about the GUI screen)

   type in: scoadmin
   this will bring up the scoadmin menu, use the <Tab> key and arrow key to move arroud the menu.

   1.<Tab> to [Hardware/Kernel Manager], use <Tab> go to [Parameters] -> [Tune Parameters]
   you will see all the options on the screen, the option you will choose are:
   option 15. Semaphones
   option 12. Streams
   option 16. Shared data
   you choose 15 first, change values as I told you in my previous comment chose the one suit you requirement. (if you don't want to change it, just type <enter>
   when you complete all the changes, type in: q to exit
   then back to the [Hardware/Kernal Manager], use <Tab> key go to [Relink Kernal] and press <enter>, then <Tab> to the menu bar [Kernal] <enter>, type:x to get backup to the main menu, choose [FILE] <enter>, type in: x to get out of scoadmin.
   reboot your system.
   job done!

   Good luck!


Author Comment

ID: 7079102
I have to try this over the weekend, I tried the "Hardware/Kernel Manager" Tab to "Tune parameters", screen message was
"Kernel Parameter Tuning"
"-g    SHMMAX"
"Incorrect line format in stune"
When I hit enter I'm right back to the scoadmin screen. Is this a configuration error or a corrupt file?

I will try again in single user mode this weekend!

Thanks again
LVL 38

Expert Comment

ID: 7080011
Why do you type in: "-g SHMMAX"

if you choose:
[Hardware/Kernel Manager] then <TAB> [Parameters]->[Tune Parameters], when you see a list of parameters, type in:15<Enter>

   It will display the parameters one bye one, and you just need to enter the value one by one untill no more parameter available for change and it will display the list again, then type in:12 ....

   It look like that you have trouble to use the scoadmin tools, please get a copy of the mannual, and have a look at
how to move arround the menu. (you only need to use <Tab>, <enter> and the 4 arrow keys for moving arround.
LVL 38

Accepted Solution

yuzh earned 2000 total points
ID: 7080994
May be we should try you luck on running scoadmin from the GUI (X Windows screen). It is easy to use, I try it on SCO 5.02 and SCO 5.0.4 a few yeas ago, I found there was some problem with the Graphic version of scoadmin (the serial device manager doesn't work !), that why I prefer to use the text mode version of scoadmin.

1. Backup you kernel first. login in as root from a text mode screen (<Ctrl><Alt> F1)
   cd /stand
   cp unix unix.wrk
   in case something happen, you can use unix.wrk to boot up your system, then fix the system.

2. Swith to your X windows screen (SCO Desktop screen).
click on the [UNIX] icon, you will then have an xterm on your screen.
   In the Xterm, type in: scoadmin <enter>
   then you have window version of scoadmin running on the screen, use you mouse to click on, [Hardware/Kernel Manager] -> [Tune Parameters], then you can see a menu with all the options for Kernel parameters, type in : 15<enter>.

   Then just do what I told you in my previous comments.

   Good luck !

Author Comment

ID: 7087637
  Thanks for all your help. I had my internet pipeline down at work yesterday. I had no way of answering you or go on the net.

To answer your comment from 6/14, I did not type in the -g SHMMAX. That was the error message when I was using scoadmin to try editing the kernel.
Same error trying in single user mode this weekend. I will try your last suggestion this evening. I can't down the server during the daytime.

Thank you again
LVL 38

Expert Comment

ID: 7091570
If you still have trouble to use scoadmin to change the kernel, please answer my following questions.

Did you built the server by yourself?, can you tell what did you do to the kernel before you encounted this ""SERVER: Warning: Only 60 wait semaphores are available"

Which hardware driver was the last one you added to your system, or which kernel parameter was the last one you cahnge. This infor can help to find out what was the cause of the kernel problem.


Author Comment

ID: 7177306
Thank You, sorry about the time it took to get back to you. The company that built the server had to fix it before I could get the parameters increased.

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