Re: Web server Partitions - swap
On Tue, 16 Dec 2003, Magnus von Koeller wrote:
> On Tuesday 16 December 2003 22:12, Karsten M. Self wrote:
> > > SWAP - 1.5GB
> > Rule of thumb: 1-2x RAM.
> I never understood that rule... In what way does it make sense that I
> need more swap because I have more RAM? Seriously, I'd really like to
> understand this.
in the old days .... memory was say 4K total ...
but the programs sizes w/ data totaled at around say 8K or 16K..
- some folks went around, when building the boxes
with 100K or 1MB disks, to allow for 2x of memory
for swap of the total memory that the machine was capable
( ie .. your program grew bigger, it meant you get
( a bigger machine and more memory -- you learned to write nice
( and clean and compact code
30 years later, its easier/cheaper to just add a new stick of memory
- having "some swap" prevents your system from doing a
random self-reboot or hanging forever whenever it runs out
of "virtual memory"
- simple test ... turn off swapp
- do indefinite memory allocation ... till it dies
( it should die at around near your real memory size )
- its a small itty-bitty program ... but it chews up lots
of simulated data that resides in memory
- the above assumes you dont have a swap file nor swap partition
- lots of embedded boxes does not have swap space ...
since it knows what kind of apps it'd be running