[K12OSN] 8 GB RAM on 32-bit Edubuntu with AMD 64 processors

[James P. Kinney III]

On Mon, 2007-11-26 at 13:46 -0500, Tom Wolfe wrote:
> .... So Jim what do you have to say about this?? From what I recall you 
> report good performance with PAE/LTSP and 16 GB RAM with 100+ users.

Yes, but not using PAE. My 8+GB RAM servers are running 64-bit kernels.
With 64-bit kernels, the RAM can be addressed directly and the paging is
disabled by default. (currently investigating clusters of lower cost
32-bit systems with maxed 4GB RAM in a single-system-image environment -
the opposite of virtualization - lots of smaller machines to make a
single large machine - Project is called OpenSSI)

The 32-bit firefox is apparently unaffected by being used on a 64-bit
system (the joys of AMD 32/64-bit architecture - can't do this on
Itanium as it's all 64-bit - Hmm, so's Irix and it had flash for the
browser...). Further since the firefox system memory is not handled by
firefox but by the system memory controller (it only 'sees' it's little
chunk and an address is just an address apparently) there's no use of
PAE there either.

RedHat/CentOS/Fedora/K12LTSP do a pretty good job with the multi-lib
stuff. I have not experimented with Debian/Ubuntu/Edubuntu in a large
environment yet.
> 
> Regards,
> Tom Wolfe
> 
> ---
>  	Tom Wolfe, IT Specialist 	twolfe at sawback.com
>  	Stoney Educational Authority	tel: (403) 881-2650
>  	Box 238, Morley AB, T0L 1N0	fax: (403) 881-2793
> Morley Community School | Chief Jacob Bearspaw School | Ta-otha School
> 
> 
> On Mon, 26 Nov 2007, James P. Kinney III wrote:
> 
> > On Mon, 2007-11-26 at 12:09 -0500, Tom Wolfe wrote:
> >> Hello,
> >>
> >> a.k.a. the never-ending quest for sound with flash on 64-bit con't
> >>
> >> I've been running gnash for a few weeks now as a solution to
> >> flash-with-sound-and-64-bit-edubuntu. For the most part it works fine, but
> >> I've noticed that it does a poor job with text in some cases.
> >>
> >> A few teachers are demanding a better solution.
> >>
> >> So I've decided to give the 32-bit Edubuntu a shot to put my eternal
> >> struggles with 64-bit to rest for a while. I know this is the tact that
> >> Jim K. has taken.
> >
> > Sort-of. The solution I found that does work is:
> >
> > 64 bit OS to make use of greater than 4GB RAM. Now also load 32-bit
> > applications for firefox, flash, sound and all related libs (ugh). No
> > use official Adobe flash code (32-bit) and magic (often. usually)
> > happens. Be sure to remove the 64-bit firefox or BAD THINGS WILL HAPPEN
> > (tm).
> >>
> >> I'm wondering though about how to use > 4GB RAM. Is this possible on a
> >> 32-bit Edubuntu with AMD 64 CPUs? If not, is PAE the solution, or is PAE
> >> only for Pentium CPUs?
> >
> > The PAE will be a nightmare for the heavily shared setup of LTSP. In
> > short, the system will thrash doing high page swaps to access RAM. If
> > all processes under current request are spread over multiple pages, the
> > performance will be beyond horrible.
> >
> > If you _must_ use 32-bit on a AMD-64 bit machine, put no more than 4GB
> > RAM in the system. Even then you may loose 512MB (depends on mainboard
> > chipset). I'm not sure if the Nvidia chips will loose RAM as all of my
> > servers using those have 8GB or higher and 64-bit OS.
> >>
> >> Can anyone point me in a direction to get me going with this?
> >>
> >> Thanks,
> >> Tom Wolfe
> >>
> >> _______________________________________________
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> >>
> > -- 
> > James P. Kinney III
> > CEO & Director of Engineering
> > Local Net Solutions,LLC
> > 770-493-8244
> > http://www.localnetsolutions.com
> >
> > GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics)
> > <jkinney at localnetsolutions.com>
> > Fingerprint = 3C9E 6366 54FC A3FE BA4D 0659 6190 ADC3 829C 6CA7
> >
> 
-- 
James P. Kinney III          
CEO & Director of Engineering 
Local Net Solutions,LLC        
770-493-8244                    
http://www.localnetsolutions.com

GPG ID: 829C6CA7 James P. Kinney III (M.S. Physics)
<jkinney at localnetsolutions.com>
Fingerprint = 3C9E 6366 54FC A3FE BA4D 0659 6190 ADC3 829C 6CA7
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