[daip] problems running multiple tv displays on different desktops

[Wes Young]

How much free space do you have on your system disk? Mac OSX is suppose to dynamically handle the swap but it's possible to run out if you don't have enough free disk space on your system disk and then all bets are off. 

As for the ports, my understanding is they are needed for communicating between processes; they also enable remote viewing/monitoring. Now I believe you can leave them on for local use but block them from being accessed from outside machines. Use to be you could do this via the sharing on system preferences but there must be a different mechanism now.

Not sure I shed much light, but your shared memory usage should be fine. I suspect your machine would have frozen up just a bit later if that memory was available. You should probably run the activity monitor it will let you monitor the resource usage for the various processes. Another option, if your machine supports it, is to run a 64bit kernel if you're not already. Not sure that would help but...

wes 
wyoung at aoc.nrao.edu


On Feb 9, 2012, at 9:55 AM, Susan Neff wrote:

> Okay - some followup here, and a new line of questions.
> 
> 
> I thought a bit about how I wanted to use my machine, and decided I'd like to have the option of running 4 tvs on the four different "desktops" I have available.  I think that means I'd want to quadruple the parameters in  /etc/sysctl.conf
> that support TVs.   After talking with my sysadmin, David Friedlander, I changed the parameters interactively (i.e. not in the file, just real-time), to see how they worked - with the idea of changing them in the sysctl.conf file once they seemed to be doing what I wanted.  I'm running on a machine with 4 cores and 32GB memory (so it seemed okay to use 68MB for TVs.  ??Perhaps this is misguided, and I should be less greedy??)
> 
> 
> I was able to quadruple shmmax, shmseg, and shmall.   I wasn't able to change shmmni interactively, so it stayed at 32 (I gather that I can change it but only in the file and with a reboot).  (I found online that this limits the number of total segments that can be shared, but I don't really understand what this means, or what a segment is.)   I then loaded the machine up, started several TV's etc.   I was also running some heavy-user CASA jobs at the same time.
> 
> 
> Sometime last night, the machine froze up.  I had to power cycle it this morning.  For a few hours before it froze up, there were occasionally a series of error messages from the kernel saying that it was out of paging space, switching on emergency paging, switching off emergency paging, etc.   At the end, just before it froze, there were also a bunch of error messages reporting attempted breakins.  All of the breakins appear to be from the Goddard IT Security folks - apparently they run automated scans every few days,  to try to break into computers on center.
> 
> 
> So, I'm trying to figure out what caused the freezeup and how to tune the machine so I don't shoot myself in the feet.  Would the non-changing of the shmmni  value, when I changed the other parameters, have let the computer get into some state where this could happen? (in which case, I could just go ahead and do the changes in the file, including the shmmni change also).   Would the attack on the machine by the security folks have taxed an already near-the-limit machine so it froze?
> 
> Or, does this just sound like an over-greedy user?  Is it likely to be the case that running big AIPS jobs (spflg, imagr) and big CASA jobs (sort, mfs clean)  at the same time caused some sort of bad collision?  (in which case, I might need to limit the TV's, or run fewer jobs at once)  Other likely possibilities?   What does the shared memory stuff required by AIPS do to the memory available for CASA?   This is all a bit of a surprise - I'm used to and expected that if I tried to run too much at one time, it would all just run really slowly - not hogtie the machine.
> 
> ......
> 
> And, my second line of questions (I hope you meant it when you said "there are no dumb questions"):
> 
> Our IT security office apparently runs these attempted breakin scans several times a week, and they seem to like the open ports used by MSSERV, TVSERV and TKSERV.  I'm running AIPS standalone on this desktop, so do I need to have these ports open for AIPS to work?   What about the XAS x-windows?
> 
> I apparently have the option to turn off all incoming connections.   It will interfere with my being able to login from home, and it will keep the sysadmins from being able to check on things without coming to my office, so I'd prefer to not do this if I don't need to.  But, I was wondering if AIPS would run with all the ports closed.
> 
> 
> A bunch of questions - thank you in advance for your answers.
> 
> -s-
> 
> 
> 
> On 2/7/12 11:13 AM, Wes Young wrote:
>> There are no dumb questions.
>> 
>> Yes allocating additional shared memory will decrease the amount of total memory your machine has available for running AIPS tasks. In practice it's a pretty small amount of memory compared to what many machine have installed, i.e. maybe 16 or 32 MB out of 2-16GB  so the impact is likely to be pretty small.
>> 
>> I doubt "set ufs" parameters would have any effect on the Mac. I found that if I striped my non-system disks I got some improvement in disk IO.
>> 
>> wes
>> wyoung at aoc.nrao.edu
>> 
>> 
>> On Feb 7, 2012, at 9:00 AM, Susan Neff wrote:
>> 
>>> Hi again, Wes,
>>> 
>>> Does the shared memory allocation impact the memory available for other AIPS tasks to use?  Does it "reserve" that much memory for the TV?   Or are they independent?  (If they impact the performance of other AIPS tasks,
>>> I might want to not run on too many TV's at once).
>>> 
>>> The FAQ also talks about improving overall AIPS performance on a Solaris machine by changing the settings to the following - will these help any on a Mac (OS X)?:
>>> 
>>> set ufs:ufs_HW=6291456
>>> set ufs:ufs_LW=4194304
>>> set priority_paging=1
>>> 
>>> Sorry if these are dumb questions.
>>> 
>>> Thanks,
>>> -s-
>>> 
>>> 
>>> On 2/7/12 10:37 AM, Wes Young wrote:
>>>> Susan,
>>>> 
>>>> In short yes, you will need to increase the amount shared memory allocation. I would guess you would need to double everything but kern.sysv.shmmin. It may be that you can get by with doubling kern.sysv.shmmax but I'm not sure.
>>>> 
>>>> wes
>>>> 
>>>> wyoung at aoc.nrao.edu
>>>> 
>>>> 
>>>> 
>>>> On Feb 7, 2012, at 8:22 AM, Susan Neff wrote:
>>>> 
>>>> 
>>>>>   However, I don't really
>>>>> understand how shared memory works - do I need to
>>>>> double/triple/...   the shared memory value for
>>>>> kern.sys.shmmax  in /etc/sysctl.conf   if I want to
>>>>> use two/three/...  TV displays at the same time?   Is
>>>>> there something else I should change?   I'm running
>>>>> with a 23 inch display, 1920 x 1200 pixels.
>>>>> 
>>>>> 
>>>>> Thanks very much,
>>>>> Susan
>>>>> 
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