Swap partition

Chris Sparks mrada at catalina-inter.net
Sun Dec 14 18:02:52 UTC 2003


Hi all,

I did try to add a SWAP file and all of the suggestions helped. I still 
tried to compile my application and
it took all of the 1G and 256MB I had as storage so I am guessing that 
there is an issue with the compilation
environment I am using. I am using a custom gcc which probably doesn't 
play nice on Fedora.

Chris

Tom Mitchell wrote:

>On Sat, 13 Dec 2003, Chris Sparks wrote:
>  
>
>>Hi Gregory,
>>    
>>
>
>  
>
>>>The "easy" thing to do in this case is abandon the miminal swap you have
>>>and just make another (larger) swap partition to be used instead.  The
>>>size of a swap partition is a matter of debate, but generally it sould
>>>be equal to or no more than twice as large as your physical memory.
>>>
>>>      
>>>
>>Since I originally started with 128 MB this makes sense why it
>>suggested 256 MB.  I had to increase the memory to 384 MB
>>because of the boat load of seg faults I was getting.
>>    
>>
>
>If your disk is fully allocated you cannot increase your swap
>partition without risking damage to the existing file systems. (a
>backup and restore will be needed)
>
>However most swap related seg faults are book keeping checks not
>active block transfers so swap to files is a good solution!
>Compare and contrast calloc() and malloc().
>
>When adding swap files, you will want to add pri=0 to the fstab
>for your existing 'raw' swap partition.
>
>Then add your swap file with a larger priority to the system and
>fstab.
>
>If you already have a swap file in addition to a swap partition
>and are still running out of 'virtual' memory you have the option
>of rebuilding the swap file to be larger or simply adding a
>second swap file at a higher priority.
>
>I happen to like having layers of swap and when things actively
>swap to the high priority swap files I likely have an application
>or mix of applications to get fixed.  Adding a swap file is much
>safer (IMO) than repartitioning a disk with data.  
>
>Do you have an old 2-4GB disk you can use for swap?
>If you can add a dedicated swap device you may want it to
>have the best priority if it is fast enough.
>
>See also "ulimit", there are lots of 'student' programs that
>would allocate memory up to the imposed limits then work within
>those bounds imposed by the administrator.  Since most students
>never had unlimited resources they never code for it.  The
>reverse may be true, check also ulimits just in case it is not
>swap that is the limiting resource.
>
>Recursion is cool but....
># bc
>define f ( x ) {
>   if( x != 1) return( x * f(x-1) )
>   if(x == 1 ) return(1)
>}
>  
>x = 15
>f(x)
>x = 200000
>f(x)
>etc...
>
>  
>





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