SUMMARY: SparcWorks Debugger

From: Milt Webb (
Date: Tue Jun 04 1996 - 15:29:35 CDT

Thanks to all that responded. I added an additional 32MB swap space and
all is working fine now.

This is the original question.

>>I have a developer that's running the Sparcworks debugger and getting a
>>"cannot fork" error followed by and "out of swap" error. So, I know I
>>need to add more memory and was wondering if anyone has a feel the amount
>>that may be needed.
>>This is a Sparc LX (don't laugh) with 32MB and I plan to add another 32MB
>>in the morning. One thing that I can't control is the size of the
>>executable he is debugging. Fully loaded with debug code this monster is
>>17MB is size. Anyone know whether that's over the 'practical' limit for
>>this machine? It's too big for some other (AIX) debuggers we have.
>>BTW, the debugger is dbx version 3.1 on Solaris 2.5

Richard Skelton
Just add some swap
mkdir /swapdir
mkfile 50m /swapdir/swap50
swap -a /swapdir/swap50
This will add 50MBytes of swap.

Marc S. Gibian
You do NOT need more RAM... you need to add swap space, which increases the
virtual memory available. RAM will help performance IF you are paging a lot,
but frequently the problem is just a need for address space.

Roderick (Rod) W. Failing III
Your executable seems a little large to me. I have only seen sizes like this in
FORTRAN code with large arrays or GUI codes that have many screens. If either
case is not true, the link command probably has a "-Bstatic" in it. This will
load all needed system libraries at link time instead of using them as run
time libraries.

If it is due to large arrays in FORTRAN, consider using dynamic allocation of
them. I know that it is not f77 standard, but it is f90 standard. Either case
it could greatly reduce the amount of memory needed.

The pratical limit is tied to the amount of swap you can allocate. For Solaris
2.x it is recommended to have 2 times the amount of memory in swap. Unlike
SunOS 4.1.x, you can have no swap but you would be suprised at how much swap
is really used, even on a 64 mb machine. We consider 32mb a minimum system for
Solaris 2.x running Openwindows, reguardless of machine type. So if you plan
to keep the LX for a year or two the extra memory is worth the price.

Mike (Mehran) Salehi
You might just need more swap, see fork(2).

Robert Pasken
         A cheaper solution (at the expense of speed) is to bump up the
amount of swap space you have. SOlaris typically underestimates the
amount of swap needed. I have seen some systems that have no swap at
all and run fine until somebody tries to run a big job (I have 32mb

George Goffe
You get an out of swap error msg? That's the 'b' partition isn't it?
I'd think that you need to repartition your system drive and make
the swap area larger.
Hope this helps...

Mike Fletcher <>
        17M is pretty huge. Worst comes to worst you can use mkfile
to create swapspace on filesystems. Not the best thing to do
performance wise, but it may do for temporary use.

        That may not be what you were exactly looking for but I hope
it helps.

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