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Old 08-30-2006, 09:23 AM   #1
cereal83
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Kernel only supports 64 GB of ram .. What do you do if you have more?


Hey all,


Well I am trying to figure something out. If the kernel only supports 64 GB of ram, well what happens to the extra ram? Does it just not get detected?

Say I have a server with 128 GB of ram, what happens to the extra 64 GB's? Is there a patch or anything that will let you overcome this ram barrier?

I really need to know asap.

Thanks
 
Old 08-30-2006, 10:09 AM   #2
haertig
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If you cannot figure a way out of your predicament, feel free to ship your excess ram to me. I'll accept it free-of-charge!

Can't say I've ever had this much ram to worry about it not being recognized. Nor enough slots on the mobo to fit it all in. Bet you don't swap much...
 
Old 08-30-2006, 10:10 AM   #3
Gato Azul
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Question Gigabytes or Megabytes???

64 Gigabytes is a heck of a lot of RAM -- at present, you'd most likely be using that much in a supercomputer environment, where you'd also most likely be using a highly customized distribution geared toward your specific application of the hardware, in which case I'd imagine that the vendor would bend over backwards to patch up the kernel for you if you really needed that much RAM. 64 GB may also be a hardware limitation -- as in the processor can't address more than that amount of RAM, though if I remember correctly 64-bit procs can address 16 exabytes of RAM.

Anyway, to answer your first question, the kernel will just ignore the rest of the RAM that it can't use. I think you may be confusing Gigabytes with Megabytes though...

Hope that helps!

Last edited by Gato Azul; 08-30-2006 at 10:12 AM.
 
Old 08-30-2006, 10:56 AM   #4
ethics
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Quote:
Originally Posted by Gato Azul
I think you may be confusing Gigabytes with Megabytes though...

Hope that helps!
That's what i was thinking, but then it'd have to be a really old kernel to support upto 64MB RAM (Or used on an embedded device?)

And like heartig says, getting a motherboard that takes that much RAM... Most domestic (obviously this is not a domestic situation) take 4GB of RAM in which case you'd need 32 slots for 128GB....

Maybe it's a hypothetical question, exploring the boundaries of the kernels and what they do when pushed. or it's some sort of distributed computing system in which case i'd love to see some piccies :P
 
Old 08-30-2006, 02:55 PM   #5
Komakino
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It was use of the words '...only 64GB...' that made me chuckle
 
Old 08-30-2006, 02:59 PM   #6
cereal83
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Hey all,

Yeah I know it seems like alot of ram but it really isn't. I am not using a special distro or anything. I am just using slackware and 64 GIGABYTES of ram isn't enough. We are adding more 16 more CPU's and 64 GB of ram to a machine but we don't want the ram to go to waste.

So does anybody know for sure if the system will just not see it and is there any patches out there that are freely available that I could use to get over this barrier?

Thanks
 
Old 08-30-2006, 03:00 PM   #7
cereal83
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Oh yeah, we are useing kernel 2.6.17 on this machine so it's not too old of a kernel.

Last edited by cereal83; 08-30-2006 at 03:05 PM.
 
Old 08-30-2006, 04:18 PM   #8
cereal83
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Nobody around here knows for sure anything? I am sure there are people on here that work with 8,16,32,64 cpu-way systems with gobs of ram.

Any help would be nice.

Thanks
 
Old 08-30-2006, 04:49 PM   #9
lleb
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im no expert, but i did find this artical:

http://www.softpanorama.org/Articles...ployment.shtml

i am not aware of a personal OS that can handle more then 64G ram.

Quote:
# High end servers (more then 8 CPUs and/or 64G of RAM with cost starting from approximately $60K). This sector traditionally called "mainframes" although in a narrow meaning mainframes are descendants of famous IBM/360 series that for twenty years (1960x-1980x) dominated the computer landscape. Currently linux has no significant presence in this segment of the market. The Linux kernel is much less tested on such configurations and as such is not attractive for large enterprises. Solaris (along with AIX and HP-UX) is the king of the hill.
when people start talking a need for that kind of power in a computer that quote is what i also start thinking about. a beowolf cluster maybe what you need to get more then 64G

sorry if that is not much help.
 
Old 08-30-2006, 07:52 PM   #10
cs-cam
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Solaris has a free version for x86 and according to this FAQ-style answer on their site, the Solaris kernel will recognise your memory fine provided you have enough CPUs in your system.

This one is talking about SPARC-based systems recognising 576GB memory!!!

Holy. Crap.
 
  


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