[daip] Trouble logging remotely into a Mac to load AIPS

[Eric Greisen]

Chun Ly writes:

 > XAS: Using screen width height 1142 764, max grey level 255
 > X Error of failed request:  BadAccess (attempt to access private resource
 > denied)
 >   Major opcode of failed request:  149 (MIT-SHM)
 >   Minor opcode of failed request:  1 (X_ShmAttach)
 >   Serial number of failed request:  24
 >   Current serial number in output stream:  25

Your TV requires 3.5 Mbytes of shared memory (1142 x 764 x 4) to use
shared memory.  The Mac operating system has to be told to allow such
large shared memory segments.  The aips manager faq page
   http://www.aoc.nrao.edu/aips/aipsmgr/index.html
tells about this problem.  It says for Macs

If you see this on a Mac, congratulations; you have one of the larger
display screens. The default Mac system limits shared memory pages to
4 Mbytes. When XAS starts it tells you that it is making a screen x
pixels by y pixels. The memory you will need is at least  4 x y
bytes. For the new large screens this is more than 8 Mbytes. On
Panther systems (X 10.3), you can change this limit by changing (as
root or admin) the rc file in /etc, adjusting the kern.sysv.shm*  line to

         #Setting the shared memory to something a bit more reasonable.
            sysctl -w kern.sysv.shmmax=10485760
            sysctl -w kern.sysv.shmmin=1
            sysctl -w kern.sysv.shmmni=32
            sysctl -w kern.sysv.shmseg=8
            sysctl -w kern.sysv.shmall=4096
         

If you are really lucky and have a 30-inch screen (2550 by 1500
pixels) then you will have to make the shmmax line even larger

            sysctl -w kern.sysv.shmmax=16777216
         

On older Jaguar systems (X 10.2), you can change this limit by
changing the SystemTuning file in

 
            /System/Library/StartupItems/SystemTuning
         

Look for the lines

            sysctl -w kern.sysv.shmmax=4194304
            sysctl -w kern.sysv.shmall=1024
         

Change the 4194304 to 10485760 (for 10 Mbytes) and change the 1024 to
4096 (allows 16 Megabytes). You must then re-boot the computer to have
these changes take effect.

Eric Greisen