[Gllug] Linux - big not small

[Jason Clifford]

On Thu, 4 Aug 2005, John Southern wrote:

> Is this true?
> Big pieces of metal must have something different, even if it is a limit on 
> swap space.
> Although, most can be learnt on anything, what are the things that are 
> different, that being unable to buy a personal s390 I am not going to 
> discover?

No it isn't true. While you can certainly learn the general system 
commands etc which will be the same systems admin depends upon a lot more 
than that and the real skills are the ones needed to manage the whole 
system which means knowing about the memory needs, file systems, physical 
storage, power and a host of other things that will be very different in a 
large system.

Even scaling up from the bedroom practice box to a simple Intel x86 based 
server running as a large webserver will involve a different skill set.

This is not to say that you cannot learn a lot of the necessary skills on 
a smaller box. You can. You just cannot equate the two beyond the basics.

> Actually, what is the limit with swap?
> When memory was smaller say 32 or 64MB, the documentation always said swap 
> should be twice the RAM. As Ram increases into the Gigabyte realms, is there 
> a limit for swap?
> Is there a reason for twice, why not x2.1 or x1.9 etc?

I think with Linux in those days it was more a matter of needing the 
additional memory resources. 32MB or even 64MB isn't a lot of memory - 
particularly once you bring X into the equation.

Unless your memory usage is very specific and you can be certain that it 
will never be more than you have in physical memory I'd recommend having 
swap. In some circumstances even if you don't use it much or at all a 
system can run slower for it not being available.

Now that vast amounts of RAM are cheap (hands up all those with 1GB or 
more of RAM on their desktop box) I'd say that no more than 1x physical 
memory is appropriate. If it were not for the fact that storage is also 
dirt cheap I'd suggest that .25 or .5 memory is reasonable.

Jason
-- 
UKFSN.ORG		Finance Free Software while you surf the 'net
http://www.ukfsn.org/	 2Mb ADSL Broadband from just £14.98 / month 

-- 
Gllug mailing list  -  Gllug at gllug.org.uk
http://lists.gllug.org.uk/mailman/listinfo/gllug